I'm not sure if the do Rx8s but you can try...
SpeedTek Long Island NY - 631-940-5967
I wouldn't trust any of the other shops in NY. There is also IRP in NJ (I go there) and speed1 in PA but those are pretty much the only options we have in the NE that is close to us unfortunately.
-93 Spirit R Replica built @ IRP. Enzo tuned