Hi!

For 6 piston calipers you need proper front wheel carriers ( with hubs ), and for that you have two choices. Fow RWD cars either GT3 or GT2 ones and for AWD cars turbo ones.
Caliper choices are from 996 GT3 / GT2 or 997 turbo. For discs OEM selection is furthermore the same than with calipers.

And now things get tricky. Proper combinations are
-GT2/3 carriers with GT2/3 discs ( bolt on ) or 997 turbo discs with 1.5mm shim/ spacer between disc and hub.
-turbo carriers with 997 turbo discs ( bolt on )

All calipers will fit all combinations above.

I have GT2 carriers with 997 turbo discs and shims + 997 turbo calipers.
At rear 997 turbo discs and calipers.

I hope this helps.

Pete