daaaaamn that's sick! You need to make a thread packed full of pics of that thing and it's setup. Is it 4/5'd + a small BD?
Tirerack wants you to "plus-size" aka same diameter as stock, but with a larger wheel. For a 4/5, 26" tire is about max. Alot of the fitment of large diameter wheels is the backspace and offset...it's a pretty tricky area that's best to figure out what fits locally, then order online or just order locally. Your current tires are probably 24" tall...maybe even smaller!
As said above, maybe check out Rangerpowersports.com.
'01 XLT disguised as a '03 Fx4 Level II.