What drolldurham said about your cranks. If you like them, remove one chainring (if you have a double) or two chainrngs (if you have a triple) and get shorter chainring bolts. Generally, people use something like a 39, 40, or 42 tooth chainring.
I had a double crankset on my old conversion and after removing a chainring, they work great. See attached pic.
A trick I picked up is that you can flip your chainring around and use your regular chanring bolts without a problem. One side of your chainring probably has part of the hole recessed so that the chainring bolts fit, if you flip it, it won't have the recesses on the other side.
You should pick up some long reach calipers. Nashbar.com has these
on sale now. Tough to beat the price for reasonable quality brakes.