Hey all,
Thanks for all the advice! When I got back from work last night I measured the rear fork(?) of my bike. Turns out it's about 130mm wide. There's also about 10mm of space left to lower the pads on my existing brakes, (Diacompo's), so I think I'm safe using them. So from what I'm reading here, I can easily upgrade to an inexpensive 8/9 speed cassette on 700c wheels. That's cool. I don't plan on spending more than $200 updating this bike. But I do realize I'm going to need, (at the very least):
-A 700c wheelset, tubes, and tires
-An 8-speed cassette, (sounds like a good compromise)
-Maybe a new rear derailelluer
-Possibly a different chain
-Definately new brake pads!
But seeing how I only paid $20 for the bike, I think this will be a fun little project.
Thanks again everyone!