Once you get the EFI worked out it is better than a carb for just plain driving. I can't see any way around that. The O2 sensor keeps the engine in close-to-perfect tune no matter the altitude, and where I live altitude is a real consideration.
Driving a carb car over Monarch Pass compared to a fuel injected car is a real eye-opener. My Mom lives at 1600 feet elevation so if I set the car up for 5900 feet where I live it's quite lean when i go to visit. Add to that the different compositions of winter and summer fuel and I will go EFI (if there is a choice) every time.

IF you are building a car and have the money to do it the Hemi would be grand. If you aren't quite so bucks-up them my 5.2Mag suggestion will work. I would use the MegaSquirt on the factory beer keg intake, maybe trim a little length off the runners like Hughes was doing. Use the 518 or 500 depending on vehicle weight.

Enough said, I started repeating myself.

R.

PS: I am starting to see some real deals on 4.7 engines, have you considered them?