You should be able to use sidepull calipers but make sure you get the right mount. Check the brake bridge and fork crown to see if they take recessed allen nuts or if you need a longer brake bolt with standard hex nuts. That could limit your options. The width and threading of your BB shell would determine what BB and cranks you could install. 68mm and English threading is the most common.
Here's an example of a budget sidepull for nutted mount:
http://www.modernbike.com/itemgroup.asp?IGPK=2126175524