Bill,
I have the March system on my car. It looks nice, and provides great accesory control even at high revs. It was mondo expensive though, and if I had a choice, that money could have made more hp somewhere else.
Any performance gain will be minimal.
However....if you honestly plan on cranking that much hp from a small block you will be doing it at the sacrafice of driveability at certain low RPM ranges, emissions, and noise. You will need to shave off every corner possible to reach that peak goal on a consistent basis.
I know I am sounding like a broken record, but you really should explore the possibilities of a big block. There are plenty of them out there from boats, trucks, motor homes, waiting for a new body to live in. It requires NO mods to your car--other than maybe hood---but you want a cool hood anyway. You will even use your same motor mounts! Plus hooker side pipes would be wicked cool on your car.
You can get the 400 hp range out of a 454 with little overall effort, no sacrafice in driveability, and you get the freaky wild stares, glares, and drooool every time you pop the hood. It is hard to get a small block to turn any heads unless you are beating the snot out of it on the strip.
Just my .02
