Originally Posted by
flayz
and yes my rims are kinda bad, like theres a bit of rust on the spokes and it kinda fused it with the nipple so i cant really true my rims 100% perfect
so if i find a wheel with a same hub or something or build one, i can just use my old 5 speed cassette?
Yes.
But I'm almost certain you have a freewheel, not a cassette. The difference is important:
http://www.sheldonbrown.com/free-k7.html
To use your original freewheel you just need a rear hub that accepts thread-on freewheels, not a (newer) freehub that accepts cassettes.