You should measure the distance in mm between your bike's rear dropouts. assuming the bike you're buying is the same, you should have no problems. You could aslo measure the hub you are replacing and compare with the wheel on the bike u r buying.

You should also get the same rear casette set up (ie, replace a 7-speed rear with a nother 7; a 6 or an 8 may not fit or at best would need a derailleur adjustment.) Your best bet is to replace the wheel with as close a match as possible.

Have u looked for just the wheel? I just sold a set of mtb wheels with nice tires and an extra tire and tubes on craigs for $25. I would think u could find the wheel if u look long enough....might take some time tho.