Hello Archer. You might like the Quax Qx-series 26" muni.It has 145mm cranks which would be good for trails. For road use I suggest you buy a set of 100mm cranks and a road tyre. I know that this will be your first unicycle,but I reckon you’re able to cycle a unicycle. Practise on the grass before going on the road
Take it easy!
Hello ARCHER, you might like the QUAX QX-SERIES 26"muni. It has 145mm cranks which would be good for trails. For road use I suggest you buy a road tyre and 100mm cranks.I know that this will be your first unicycle but I reckon that you have some unicycling experience.Practise on the grass before going on the road.
Take it easy!!
Hi Archer - IMO the best single size is a 20 and a 29. Buy the 20 first; make sure it’s a decent one because when it comes time to sell it (after you buy your KH 29er) you’ll end up wanting to keep it because its so much easier to take on car trips, and its the right size to convince your best friend to ride. In hindsight you’ll find that buying the 20 to learn on was the smartest thing you’ve ever done.
Also, IMHO as a relatively new rider (18 mos) - don’t try to learn on grass, it was way harder for me and I hear that’s typically the case. I was riding a mile or two in a couple of months; it was several months before I could do a loop around d the local soccer field.
Sam
I would never sell my 20" 
Seriously, it’s good to have a 20" for practicing skills like wheel walking, one-footed riding, hopping, all good skills which help you even if your main activity is road riding or muni. Being able to do these skills makes you a better more confident unicyclist.
I didn’t sell my learner 20", but I have given it away on long term loan. I bought a nice lightweight custom 19" to replace it with - I wouldn’t have known what bits to buy before I started, and nor would I have wanted to splash that much cash. I don’t regret for a minute buying a really cheap uni to learn on - if I had bought a more expensive, better quality 20" uni I would still have wanted to upgrade.
So my recommendation to the OP is to get a nice cheap 20" (or maybe 24" - I understand they’re not much harder to learn on), one which you won’t mind losing the money on if you give it up. Unlike bikes, and various other sporting equipment, you really won’t notice the difference with a cheap uni when you’re just getting into it.
I will be keeping the 20" I learned on for two reasons.
Firstly, I can teach other people to ride it and, secondly, it is perfect for riding round the park with my wife in her electric wheelchair 
I agree with it being great for practising new skills on too. Once I decide to try idling or riding backwards, I’ll be back at the tennis courts with it.
Hello Sam.If he buys a Muni as I suggest, then surely the grass is best.With regard to cycling a 20" some distance, you are correct.The grass would be tiring. But for a beginner learning to mount and ride a few yards/metres,I would suggest the grass.
Personally, I find grass to be the most difficult surface on which to ride, because you can’t see where it’s soft or bumpy. It’s nicer to fall on but harder to ride.
Thanks for the help and advice everyone. I decided to go with a cheaper, more street oriented uni for my first purchase. I did go against most advice of getting a smaller wheel size and I got a street 29er but I like a challenge and everyone can say " I told you so" when I start posting about mounting issues. Here is what I went with:
I upgraded to the KH freeride saddle as suggested. I selected the standard 125mm cranks but also order the nimbus ISIS 150mm cranks to learn on that were on sale for $25. Im in a very hilly area so I may end up liking those better anyway. Cant beat that deal, and the reviews say this is a quality uni. The weight also appears to be rather low. Once I get proficient I will order myself a nice KH 26 MUNI with a 3" tire
While it is cheaper than a KH, that’s not exactly what most people had in mind. 
Still, at least one other person has learned on a 29" so get out there and practice!
It’s possible to learn on a 29. “With sufficient thrust, pigs fly just fine” as they say :p. I think the 150mm cranks were a good idea. Extra control is what you need at the beginning. Also make sure you have whatever padding makes you feel safe. Confidence helps. It’s hard to commit to leaning forward and riding on your own when you’re nervous about getting hurt. If you’re not sure what to get, use the search box. There are lots of threads on the subject.
Good luck. Keep us posted on your progress.
If it’s VERY hilly in your area, then use the long cranks.Be careful going down hill that the cycle doesn’t pick up too much speed and throw you. You’re going to have a job mounting it ,?especialy going uphill. A brake would be handy for control on steep hills!!! Hope this helps
Ur
Hello tholub. Iguess it’s a question of preference.When I first learnt, it was on the grass with no support.I just made a small groove in the ground and slotted my tyre into it.That really helped to stabilise the wheel.And I learnt to freemount from the beginning.E ven when I bought my 36er,I did some hours on the grass before venturing onto the cycle path.
Learning on the grass surface with no railings or concrete to fall on just made me feel more confident. Some grass surfaces are not too bumpy.
Dont worry guys, what I lack in skill, I make up for in confidence. That should take me all the way until the box arrives on my doorstep anyway.
I should film this for all to see. “Crazy guy thinks he can free mount 29” unicycle with no previous experience." Come on, cant be that bad right?
What could go wrong?
You’ll be fine, sure it’s harder to learn on a bigger wheel but realistically probaly only a few days difference at most. Oh yea, nice uni. Should do the trick for you for awhile, at least until the addiction kicks in 
In a few years you will own all wheel sizes and a Schlumpf hub. Be prepared:D:D:D
A few years? OK, so I’m still lacking a 36, but I owned a 19, 26, 29 within 7 or 8 months of starting, and got my Schlumpf after just over a year (admittedly I’m still working on mastering the Schlumpf - is rather harder than I expected).
You’ve got yourself a decent uni there
Like unibokk mentioned, quax would also have been good. Personally, I’d rate the quax and the nimbus models as being just as good as the KH ones, especially when you take the prices into account.
If you’re learning to ride on the 29er, then I’d suggest, if you aren’t making good progress on the 125mm cranks, to swap in the 150s- you’ll have considerably more control, especially if you’re trying to free mount it.
And, if you’re in a hilly place, bear in mind that some 29er riders, myself included, prefer 150s overall.
KH ‘dual-hole’ cranks are very useful- I’ve got a pair of 150/125mm ones which enable quick and easy changes of crank lengths, so you can experiment by switching lengths on rides.
Concerning getting a 26" uni with a 3" tyre- it sounds like a good idea, as it means it’s almost as big as a 29-er, but, as you live in a hilly place, bear in mind that that 3" tyre is going to weigh a hell of a lot, and, IMO, going up steep hills with a heavy tyre is not much fun.
I did use a 3" tire on my 24" nimbus, and was totally happy with it. But, I found a 3" tyre on a 26er to be overkill.
Personally, on both my quax 26 and KH 29, the first thing I’ve done on getting them, is take off the stock (heavy) tyre and find a lighter option- it’s amazing how easy it is to slide up the hills once I’m not dragging around an overly heavy mass of rubber.
Also- don’t fixate on the KH26- the quax26 is, IMO, a brilliant unicycle- if you can get one cheaper than the KH, it’s worth considering. Just like the KH it has an aluminium frame, but also has the advantage of not being blue