Nice car...try lowering it one inch all the way around and I think you may be surprised how different it looks...
As far as drivetrain...good choices...If it was mine, I'd go mild solid lifter, just to accent the Shelby look the car has. Something like the original HiPo cam would work fine...the rest of your choices are great IMO..
You could approach 1 hp/ci at the crankshaft if tuned right, even running a stock 4100 Autolite instead of a Holley...
Personally, as a mature racer *G*, I prefer the wolf in sheep's clothing look, like my D-coder has, with its skinny tires and sedate paint job. Only hint is the rumble at the rear bumper..*G*
Have fun and let us know how it goes!