Hmm...I don't know where to start.
Aircraft engines have whole different set of specifications and reliability is a paramount. That's one of reasons we still see WWII technology in small aircraft engines. It's tried and true and few dare to change it.
Have you checked that such alteration of your engine is legal to begin with? I mean, you cannot just "park it on a hard shoulder" should that supercharger belt snap...
Even if you decide to do all this by yourself, I firmly believe supercharger is the worst option, and centrifugal supercharger is worst option in superchargers. Superchargers are inherently less reliable than turbochargers as they have many moving parts. They are also less efficient. Actually, only good thing with them is that they give instant boost but that's quite unimportant in your case as you will never slam your throttles so fast that it will make any big difference. Aircraft engines are usually operated in steady,continuous manner for longer time. Centrifugal superchargers have to spin almost as fast as turbochargers, which means complicated and power-eating gearboxes. They also have annoying side-effect of boost raising proportionally to revs. So for low-rev boost you either have to gear it high, and then waste excessive boost when higher up in rev-band, or gear it so max boost hits higher up.
As I said before, I believe you should be very careful with fiddling with aircraft engine yourself as your life actually depends on it.
If you really want to build some sort of supercharging device then I recomend turbocharger wholeheartedly. It has only one moving part, it is actually developed for aircraft use from beggining, it is more efficient than supercharger as it uses otherwise wasted heat stored in exhaust gases etc.
I don't know much about aircraft engines but as far as I remeber there are two main turbocharger designs on smaller single-engined airplanes:
1. Turbo-normalizer, that just keeps intake pressure at constant level, independently from height (which means that turbo is "making up" for thiner air and keeping output constant)
2. Turbocharged, where you actually see positive manifold pressure.
Once again, please be very carefull and do lot's of research with people who are familiar with your particular engine.
Here is a link to marvelous series of articles, written by John Deakin of AV-web.
http://www.avweb.com/news/columns/182102-1.html
He covers exactly the very thing you are planning to do.
You would want to build something like this:
There are many turbochargers that would work well with 360ci engine turning at 2000 RPM. From the top of my head, Garrett GT35 would work fine.
And no, I don't think you want boost from idle. Boost from idle would force you to use too small turbo, which also means high backpressure, EGT and compressor operating in non-efficient region while take-off.
Yes, I know that you have lot's of expirience with superchargers but I'm sure that turbocharger is better/cheaper/safer option in this case. With little luck, you'll be able to find a kit for your engine.
Regards.