the Speed Channel Touring car Realtime Racing ITR and the GrandAm Series ST1 class Planet Earth GSR's from last year (which have been sold to some lucky bastard) use 15 in. rims and AP Racing or Brembo brake calipers....they fit on our cars and are streetable.
...no big brake kit and the need for 17 in rims here.
That AP Racing caliper pic on the post above IS on a street ITR not a race car. have you looked at the price of Spoon calipers? AP Racing are close in price....
As for streetable pads...I didn't say Porterfield R4 or Hawk 9012 Racing or Panther or ATS carbon pads...which would make you sound like you were killing a cat every time you broke.
I did say the R4S which are street/track versions...good wear longevity, low dust production, good friction range but gentle on rotors, and great heat range (fade resistance) without the noise...I prefer them over the Hawk HP Plus (which are street/track pads).
Spoon pads are just Nissin pads (makers of Honda OEM pads as well) that have been upgraded slightly and AEM pads are the same thing at a lower cost.
The other brand other than Porterfields are the Endless CCS pads...nice:
and Endless do make a line of 4-6 piston caliper kits for all tegs....