No one makes a titanium caliper. It's not a good choice of material for the application. Brembo does make titanium pistons for the calipers. But you need drug money to buy those. I have them in my Brembo mono-block calipers on my bike.
For a light weight front and rear BBK. You will be spending $6,000 and up.
https://www.stillen.com/ap-racing-ni...ssan-370z.html
https://conceptzperformance.com/Cart...ype=370Z&CA=24