I used a Wilwood Dynalite 4-piston kit and they work great, even with paltry 11" rotors. Kits start at $700.
https://www.summitracing.com/search/...03-in-280-16mm
12.19" rotor kits start at $1,020:
https://www.summitracing.com/search/...rder=Ascending
GM calipers, 11" rotors, $400 kit:
https://www.speedwaymotors.com/Musta...tern,2008.html
13" drilled and slotted rotors, 2-piston calipers, $1,000:
https://www.johnnylawmotors.com/cata...k-pro-spindles