the only ones you can look at as a direct or semi direct swap are 2 piston JDM brakes off their st185's or st205 4 spot calipers - which require some modification ..
the 4 spots are VERY HARD to come by and premium prices are asked for them
outside of that - custom fabrication is your only option
r33 skyline gtr brembo brakes have been used by a member of this forum with good results but it was a total custom fit