A couple of things I'd add -first off, what kind of shape is the engine in now, how many miles, what kind of miles? A mistake that's often made is boost is applied to a worn out engine, and whatever problems might have been there are made worse by the addition of boost. Mileage in and of itself is not necessarily a problem, but if you've got more than 80k on the motor or the motor has been used really hard, I would not consider adding the supercharger until I had first run cranking compression and leak down compression tests to be sure the engine had the integrity to stand up to the boost. That way you're not surprised later.
I don't think anyone has talked about intercooled/non-intercooled. Superchargers heat the intake air significantly when they compress it. The warmer the intake air (all else equal) the less power is made. Also, the cooler the intake air, the more timing and the less rich you can run without fear of detonation - and cooler intake air, more timing, and less rich mixtures mean more power. So I think a threshold question is are you gonna intercool it or not. You've got enough info in this thread that I think you should start talking to the various supercharger companies now. They can offer you detail about pricing, configuration, boost levels and how you'll have to alter the tune/fuel/timing to run the boost safely. Good luck with it.
