I have no clue about unicycling or anything remotely related to the outdoors or exercise (sorry) but my big brother just loves anything and everything to do with outside, learning tricks and doing cool stuff that not everyone else can do (and if it has any risk of maiming or death, he’s right in there!)
…so, i want to get him a unicycle for christmas (its one of the few things he hasnt tried yet). the thing is he’s 6’2" and a lot of the ones on ebay (i know, i a cheapskate but hey, im a student) seem to be pretty small (24" was the tallest i found) so i was wondering what height i should be looking for and if you could recommend anywhere that sells them cheap.
if money is an issue i would get a 20" torker lx. if money is not an issue i would get the torker 20" torker dx. 20" are usually the best to learn with. You should get one along with buying your others. When I started my friend and I would have competitions to see who could go farther. I think that watching someone else screwup helps you not screw up and both of the learners lean quicker
a begginers 24" is probaly just fine, or you could get a 20" and make sure the seat post is long enough. i dont know where the cheapest place is but ebay is a good start, hope you find one.
20" and 24" Torkers usually ship with a seatpost suitable for tall folks. I’m 6’0" and am able to ride comfortably on a 20" DX.
eBay’s your best bet for low price, but forget customer service… if you can afford an extra $10 or $20, go with an on-line retailer (as opposed to the wholesalers you’ll run into on eBay) and you’ll have someone to call if anything’s wrong with the uni.
Do a little homework and check the Better Business Bureau file on your retailer (you can search from the BBB’s web site) before making the purchase… some on-line retailers are dirty crooks and you won’t find out until it’s too late!
Wheel size should not be related to how tall the rider is. Seatpost length is related to rider height. Tall people can ride 20" unis just fine, and I’ve seen people 5’3" on a 36" uni. The larger the wheel, the faster you go, the smaller the wheel, the more tricks and skills you can do on it. 20" and 24" are by far the two most common sizes, with 24" being the best for normal riding around town and most tricks. 20" is great for lots of tricks/skills, but slow for distances. There are also Munis (mountain unis) which are 24" and Trials unis which are 20" Mod (fits a 19" rim) but those are both expensive. The Torker LX is the strongest cheap unicycle out there, and is available in both 20 and 24" sizes. I own a 20" torker LX and highly recommend it (or the 24" version).
I would suggest the Torker LX off of ebay. It’s the cheapest decent unicycle you will find anywhere, I think.
As for the size of unicycle, they are measured in the diameter of the wheel. So a 24" unicycle has a 24" diameter wheel, which is a good size to learn on (probably better for his height, too).
If you think your brother will want to learn a lot more than just riding around, then you may want to get the 20" unicycle. It’s better for tricks.
I would say go online to municycle.com and look there they have the best unis ive seen.And it would probably be good to make sure he has plenty of protective gear for the beginning!!!
I have no clue about unicycling or anything remotely related to the outdoors or exercise (sorry) but my big brother just loves anything and everything to do with outside, learning tricks and doing cool stuff that not everyone else can do (and if it has any risk of maiming or death, he’s right in there!) 
