LOL - that's the trouble with slim cars I guess.
Si has used the Futaba Rx so maybe you'll be OK. Don't forget the Castle is ma-husive.
Lo-Pro servo is nice though - does free up a fair bit of room.
I think you'll get the ESC on the chassis no prob - might need to be a bit ingenious with the Rx.
I'll post my install up in a few days - just trying to keep pace with everything right now
Cheers