Sorry to revisit an old debate but...

I LOVE the angry hornet sound of a hot /6!! Id turbo it personally and keep the comp low for better fuel consumtion. In this day gas mileage is king,but you can have your cake and eat it too with a turbo. Bill Deadman has a GRREAT thread rolling on turbo slant builds.Also the /6 is VERY budget minded and you can still get parts no problem.

But seeing how you want a small block I'd get a teen or 360,as there are still plenty around. A magnum engine will definitely get you a roller cam,as will some of the late model (85-91) 318 la motors. Look to Summit for your hop up parts,they have very reasonable prices for headers,exhaust etc etc.