stock wheels on Trackers can be reversed with little bad consequences. ONly thing to watch out for is to make sure that the wheels are not LSI wheels!! They CANT be reveresed (at least all the ones Ive seen have a little more backspacing to prevent them from being reversed.
Also, I dont think the fancy wheels can be switched, just the basic 5 spoke Tracker wheels. I actually got my spare wheel at the junkyard off a Tracker with reveresed rims. Looked pretty sweet. About as wide as my 15x7 rims.