To the original poster - if you want to run a supercharger, remember that you have to make a bunch of extra power to turn the supercharger. So take that into account when you're deciding whether to use a stock block. The crank also takes a heavy load from the pulley running the blower. I've always heard around 500 hp as the magic number for the stock block, but essentially more power = shorter life. You can make it live at 500 hp, just not nearly as long as it will live at 400 or lower. If your net out put is 400 hp, you might be making 500 hp and using that extra 100 hp to turn the blower.
Another option (not cheap, but cool IMO) would be to run an aftermarket block with big cubes at the 8.2" deck height. NA you could make lots of power and have really good longevity. Bigger bores unshroud the valves for better flow, so a big bore aftermarket block can make a lot of power. If you went with an aluminum block it would be really light in the car, too.