If you talked to Art Carr, and explained the application, then he's the man. I doubt you'll find anyone on this board that knows as much as him. That is, as long as you've explained how much freakin torque you'll be making - this ain't no chevy!
Regarding thermostats - definitely get one. A 165 is fine for what you're doing.
And for full disclosure, mine's a centrifugal supercharger, not a roots. I bought it from someone who claims to have mounted it on a Buick 455, however after doing more research I realize that they made everything themselves (including the giant hold in the inner fender, for clearance). So since that isn't an option for me, I'm stuck with a supercharger and no brackets or pulleys. I've tried to get brackets from others, but no real luck. It's too bad, because my 455 is fuel injected and would be SUPER easy to tune. There used to be a company that sold a whole kit, but they're gone and I just can't seem to get the brackets going. I'm SO close, it's sad, but I just don't know how to go the rest of the way! Do you know anyone with a SBC that wants a Procharger?
One more thing. With regards to lockup converters, they are generally only found in the 10" and larger converters, I think. But with the mountains of torque you'll be making, a 10" or 11" would probably be just fine. But there may be a limit as to how much torque they can handle, I suspect you'll be capable of breaking yours...
Oh yeah, and don't forget to beef up your driveshaft and rearend too...
-Bob C.
