A fork will do OK for a front wheel and be a stretch (quite literally) for any rear wheel and won't have any indicator pointers for true or hop unless you get a salvaged brake caliper too.

Amazon is selling the "Sunlite Deluxe" truing stand for $60 with free shipping and it stands on any flat surface and folds for storage. The reviewers give it 4 stars so it's at least functional. It looks very much like a cheaper version of the old Minoura stand which sells for 2.5X as much also from Amazon. Here is the link:

http://www.amazon.com/Sunlite-Deluxe.../dp/B000AO7GDK

REI has the Park "Home Mechanic" truing stand for $100. It's nothing elegant but should work for what you require. Here is REI's link but you might find it for less elsewhere as REI is almost never the price leader:

http://www.rei.com/product/722266/pa...:referralID=NA

With either of these stands (or almost any other model too) you will need a dishing tool to be sure your rims are centered or be willing to flip the wheel over frequently as it is trued.