warped rotors will not ussually cause any vibration whil driving, but it sounds like who ever re-sufaced them did't know what they were doing, or had to much runnout on there brake lathe. my advise is to replace the rotors, having them machined will cause them to warp even faster, heat crack more easily, ect. have your tires balanced, checking for flat spots of course. and make sure that you tourqe your wheels back down properly. if you can find a shop with the right eqp. also check to be sure that you don't have a sticking caliper, uneven pad wear from side to side. good luck, hope this helps.
96 gt, damn it's slow. bolt ons 3.73's, nx 150 shot ect.