Which LS Engine?

[kiwigt]

I'm starting the build of a 69 Camaro that I'd like to be sort of an 'iron fist in a velvet glove' - an AMG Camaro if you get my drift. A somewhat luxurious PT car, with the emphasis on the touring part of the equation.

I'm committed to the full DSE catalogue, and the car must be auto gearbox.

I want a new crate LS engine; about 550-650fwhp I guess. Engine has to be run by a GM computer - no other setups such as Mast etc.

If money wasn't the determining factor, which LS engine/auto gearbox combo would you recommend for what I'm trying to achieve?