The 993.352.425.10 and 993.352.426.10 are 993 turbo rear calipers that use a 322x28 rotor...these should have 28/28mm pistons. So a 309x28 930 rear rotor will work on early 911's.
Hard to tell from the pictures if the used set are "Big Reds" or "Big Blacks/S4.... but Big Reds have 44/36 pistons.
If Big reds....they use a 2 piece 322x32 rotor...If Big Blacks, these use a 304x32. For narrow body cars a caliper adapter and a 32mm front rotor or a pre-1980 930 rotor without the 930 hat. You will have to use a custom hat for those floating rotors. If using 930 wide hubs (1981 930 and on) these late 930 rotors will work and are 304x32.
Pads will be whatever you decide fitting a 993.
Rear calipers will need to be re-drilled or the Ears cutoff and re-drilled radial style with adapters
Fronts only need the proper caliper adapter
Check here for info on re-drilling the rears:
https://forums.pelicanparts.com/porsche-911-technical-forum/993492-74-widebody-hot-rod-build.html
Check here for caliper adapters and caliper modification:
Vehicle Craft Inc."VCI" Hi-Performance Brake Upgrades For Porsche Cars