it will for sure work. I wouldnt worry about stopping power or whatever. itll work. my brothers 70's centurion takes a 700c without even moving the brake pads!! just to describe, heres what 4mm looks like : __ wow, not as far as you thought huh? the the threaded section of your brake pad is probably 5mm in diameter.... id say change the pads before you flip out and buy a whole new brake setup. spend the money on cable and housing. new rims + new pads should = some good braking even with a centerpull.
if you have access to any major distributors, j&b has a good price on an ultegra hub/mavic openpro rim set. good strong all around wheels.