The Wilwood Aero6 caliper is an amazing value and absolutely an upgrade from the OEM Brembo. We tried to make the SL6R caliper work but we only gained weight reduction but worse braking performance.
Unfortunately I have not be able to get a vendor account to stock calipers but if looking for them on the wilwood site, select Aero6 -> 6 piston -> 1.25" rotor width -> 4.04 piston area.
Then is important to make sure 5.2in2 pad area. This is the same thickness at OEM pads and will give slightly more rim spoke clearance than OEM Brembos. The thicker pad is 3mm bigger and has a different offset.
For Example, this
These radial mount brackets spacer the Aero6 to match both OEM Evo 7/8/9 and Evo X rotors.
Pad recommendations are Carbotech AX6 up to XT10 for autocross, and Raybestos ST43 or greater for track.
The XT10 is a great dual purpose pad in my experience but the ST43 does not play well with Evo ABS at AutoX temperatures.