Using the RWD VQ35 doesn't make it any easier. The same stuff would have to be fabbed to make it fit correctly. Combine that with the 350Z motor costing a fortune, and the ECU being setup for throttle-by-wire, the choice becomes more apparent. One of those guys works at a Nissan auto recycler, so if OEM parts existed to make installation easier, he would have used them!

This still doesn't answer the complete question, since we're ignoring the turbo part. I'd imagine once you finally got a VQ into a 240sx and working, hanging a turbo wouldn't be more than an exercise in pipe routing (and a hell of a lot of welding). With the short V6 motor in that long engine bay, you could do one of those cool front mounted turbo setups like you see on Mustangs....