Originally Posted by Skewer

Yes, you don't need to change the entire brake caliper; imo you should just be able to install a new pad holder/pad combination in to the old calipers. And you can get one piece, integrated pad holder/pad styles like these Serfas below for very few dollars:

http://www.rei.com/product/752081

Kool Stop, Shimano and all the rest of the pad manufacturers make inexpensive one piece, integrated holder/pad models like the ones pictured above as well.