Yep just bought 4 new calipers, it's kind of hard to be frugal! Some of the things I noticed on mine were stuck pistons on the front, the rear calipers were full of goo never beld correctly, very uneven brake pad wear between the calipers, looks like one of the rear calipers was doing most of the work. I had all my rotors turned. Some of my calipers were aftermarket sleeved with lip seals and some were stock, only one rear caliper was a rebuild candidate. My local Vette shop accepted my cores, most places I found won't give a credit for sleeved cores and that was my biggest obstacle. So I got four new lonestar SS O-ring calipers for 400 bucks and they are the stamped Delco Mor's. I am shopping around for SS lines and new pads right now.  

Someone smarter than me will hopefully correct this if I'm wrong. I'm doing my brakes now and this is what I've learned so far. Calipers can be rebuilt if the cylider walls are not corroded. You have to break them down and inspect them, it's real easy. You want your rotors to have uniform straight surface as they spin where they make contact with the pads, if they have too much runout (warped) it will pulsate the caliper pistons causing air to be drawn into the system through the lip seals, I just learned that myself   Also it will cause stress on your wheel bearings, cause noise when braking, pulsating brake pedal, and uneven pad wear. I always let a shop mess with my rotors, it's fairly cheap about 5-10 bucks per rotor,  they will turn them so they are true, basically they put them on a lathe and resurface them. Most rotors can be truned unless they are really warped or don't have enough thickness on them left. After that I throw them back on the spindle with new bearings and then check with a dial gauge if you still got probelms it's time to take a closer look at the spindle.