junkyard brakes

[95silver/blkgts]

i have a 95 gts.i need to replace both front rotors and i was thinking of going to the junkyard and getting the calipar bracket and roters(if they good if not aftermarket.summit).my neighbor has a linc. town car and it has at least 13'' they might be 14 it was hard to tell.also i would like to get rear breakes to grab better.should i install a proportioning valve(whatever kind of valve.thanks for any help with break upgrade

 

[ScratchinFerTra]

For what it's worth, I installed 4 piston 13" Aerospace Components front brakes and was told I did not need to modify the bias. It works fine, and you can tell the difference with the larger rotors and better calipers.
Stan