I am looking to replace the front calipers with a 4 piston caliper. Has anyone used any aftermarket brands to give me some insight on what way to go? I am using a aftermarket rotor drilled and slotted and would like to keep them instead of buying a entire kit.

 

i would look into a rear disc conversion before buying 4 piston calipers for the front

 

Sounds like you are trying to spend some money. You could do a simpler upgrade and get the 85 SVO calipers with the 73MM steel piston for alot cheaper.....but that doesn't compare to 4 piston..