I just borrowed my buddies torker lx a few weeks ago and before I even got off the wall I new I was hooked. I’ve been riding just about every day since. Last weekend I bought a 20" muni off craigs list. I love it and can’t wait to get a 24" muni. I also need to give the torker back and want to buy a road worthy uni, like a 29" maybe. I had a unicycle for a while when I was about 12. I had no one to teach me so I tried endlessly to free mount in my driveway with no real success. Now 28 yrs. later I stumbled onto this (enabling) site somehow one day a few weeks back and learned that you need to start with some sort of prop (wall, fence, chair back etc.) I new I could learn right away.
I should have never taken that first hit, now there is no turning back!
Welcome to the madness. If you really get hooked you’ll have 4 or 5 of these before you know it.
Yeah, welcome back 
If you want a 24’’ Muni, you probably don’t even need an entirely new unicycle. It looks like you could probably fit a 24’’ in that frame already; measure the distance between the top of the wheel and the frame, and if it’s more than two inches, you can fit a 24’’ wheel in there. You’ll just need new cranks/pedals and a wheel rather than a full uni.
Check the bearing sizes too. I wouldn’t be surprised if those were 40mm.
And welcome. 
There isn’t enough room on the sides for a 24" tire. Besides I want to keep the 20" off-roader. There is a 24" torker DX for sale localy for $200. I kind of want a nimbus or kh but it is in good shape. I would buy it if I thought I could sell it and not loose money when and if I were to replace it. Any body have any opinions on a DX for $200?