RS Motorsport :: Classic Speed Restored

Gidday,
I have a wee self built Sports Racing Car.
Nissan SR20 Turbo, 298HP, 600kg plus, Sicks all round, 9" rims on the Front and 10" for the rear.
At this point I have TF Cortina uprights and Discs with Volvo 4 spot calipers and 3000 Ferodo pads and bias adjustment.
The rear has Pintara Calipers and Alfa discs using Lucas pads.
I want to slow down quicker than I do now presently.
Are there Calipers around that I can fit bigger pads than the volvo's bearing in mind I a stuck with 13" rims. I have about 12mm clearance to the inside of the wheel.
Same applies to the rear, what else is available ?
Thanks,
Les.

What rotors are you using? If you're using Capri 247mm you can go up to 260mm with BMW E30 or TX3 Turbo (DBA101) rotors. Not a huge change but would give slightly (and only slightly) better swept area and torque...