Hey Pops
For my calipers I am using '86-'91 RX-7 Turbo calipers, they are dirt cheap 4-piston design....the bad news is the spacing is 158mm (6.222") centerline to centerline.
I'm making bolt-on adapters for my application
My rotors and hats are going to be from Wilwood....
Wilwood does have a brand new caliper out that is radial mount (mounting holes are 90° from the axis of the spindle compared to the stock mounting holes which are parallel to the spindle)...these are about $150 ea, but that price does not include the mounting bracket. I'm waiting to hook up with a Bug/Type III guy up in my area, once I do, I hope to be able to take some measurements and see what we can do for your car.....