By my estimates a kit would cost about $5500 in parts (for about 5 PSI of boost). For higher levels of boost (10 PSI), the engine would have to be sleeved, forged pistons added, compression lowered, and the valve train reworked (which would add additional cost).
At this point I am just curious who else is interested. I have worked out which parts are best suited for the Lotus Elise and the Toyota 2ZZ-GE engine. This took many weeks of time and I think I have solved the most difficult design issues with the exception of tuning and/or engine rebuilding.
I would like to use this thread to discuss the topic and to help me work out the finer details.