The problem with using the Renesis in its 'factory' configuration is all the electric solenoids, intake staging, and the before mentioned drive-by-wire throttle body. I have seen a Renesis in a first gen, but it was an entire conversion, interior, dash, nearly everything.
This is the hardest/easiest way to do it.
Here is a couple pics for your pleasure.
I can't find the interior pics anymore, but it basically had the RX-8 cluster and center stack in it. Since the RX-8 is CAN-BUS, it needs all that.
One other issue with the FB swap was that the steering fault light was always on (since the car had a manual set-up, and the DSC doesn't work since the car had no wheel sensors or the yaw sensor.