Todd-
I think you forgot to include another parameter-- price. If money is not a limiting factor, I would go with an aluminum FE block stroked to 484 (or bigger) with a nice hydraulic roller cam. You would have all the hp and torque you could ever want well under 6k rpm. Granted this would likely cost the better part of 20k, but I think it would be a great street motor. I have been considering picking up an aluminum block and over the next couple of years buying the pieces and building one myself- with the exact same parameters that you have in mind.
(And BBs are better than SBs- just kidding)