Same as that never seen any other calipers on the back other then the shock ones . i am sure you can fit any caliper you want but pointless as 80% + braking is done from the front calipers
try and get this kit to wind back the piston well worth the money
http://www.ebay.ie/itm/Universal-22pc-Disc-Brake-Caliper-Piston-Rewind-Tool-Kit-Set-Auto-Wind-Back-Car/131647098239?hash=item1ea6c74d7f:g:RtIAAOSwY4pZX3k6
I was going to do the same with my glanza boot lid to smooth it but i was going to fit the lexus is200 fog lights as i was thinking it would be to bare other wise