running the MSD 6-Hemi ?

I am thinking very hard on doing the swap, and I want to inject it. Not sure on how to go about it, use stock pcm and modified wiring harness and diablo predator for tuning, or use FAST system. I have never used a megasquirt but have heard is not user friendly when it comes to the tuning. Anyone using the FAST system and is it a just a plug and play?

Trevor