rx7 caliper width and compatible Porsche rotors?

[pribs67]

I'm looking to do a big brake upgrade along with an IRS conversion. I'd like to use RX-7 calipers as they seem to be highly rated and quite a bit cheaper than the Porsche calipers and will, in addition, fit under my 15" Fuchs. Does anyone know of a Porsche rotor that will be compatible with the RX-7 calipers, or a source for blank rotors that I could have drilled to work with a Porsche hub? According to the Brembo site, minimum width on the rotors is 20mm. Thanks.