yeah, i have done that. That side of things is easy. I have been talking to Lindsay Stone about this little idea of mine. The perfect dude to chat to as he run a rotar and used to help with the "Dazda" rally cars back in the day.
Basic list of requirements:
Has to have the same or equivalent brakes as to what was on the car the engine came out of. (disc front and rear)
Mechanical E-BRAKE - as with all legal road going cars
Suspension - has to keep the car on the road -- the front end will be a different weight so, has to be taken into account.
Has to be an "inline" pressure relief system for the turbo gases -- no stinky noise BOV
Has to meet the emissions at the time the engine was put on road - both noise and GAS
Stuff like that.
I am more after the nitty dritty bizzNATS of fitting the engine and box... The things people cannot plan for until they're holding an engine and box in place