Things for the Prelude aren't THAT hard to come by, but there aren't enough choices between manufacturers (e.g. cams, headers, etc.).
Grant's car would have to get quite a few things changed to make the car streetable. Also, Grant's car leaves much to be desired, unless he has fixed is brake and engine reliability problems. Suspension-wise, the car is set up very well (although I haven't seen his new Moton dampers). The cage is well built, and the car is quite light (for a Prelude). The car is a runner, there's no doubt about that, but he had some horrible reliability problems last season. He didn't even make it to the season opener here in Texas because of brake issues (according to a WC official).
It's hard to get off the shelf stuff for the Prelude because the demand is not there. I mean, there is some demand, but no where near the demand for Civic or Integra parts. It is quite sad as the H22 is a very strong engine.
As for engine builders, anyone that is familiar with Honda engines should be able to build a strong H22. The weakest link are the rods. Of course, the build depends on how you are going (NA or FI) as well.
The Endyn SC was talked about for a long time, but so far I haven't seen a Endyn SC on any car besides Larry's. However, Larry does do JRSC modifications that make the blower much more efficient and capable of more boost. Now, if you are willing to pay for it, you could always have a custom SC made. Everyone was hot to trot for the Endyn SC until rumors about the cost being up to or over something like $7k started. People just balked at the price, but that's the price to do things the right way. The Endyn SC does exist. I have seen the Type R and ridden in the Civic. I am sure that for the right price Larry will reproduce those kits. As for now, a production SC for the Prelude is vaporware, but Honda's are not Larry's mainstay business (unlike JR), it's more of a side business. Also, unlike JR, if you ask Larry when the Endyn SC will be out, his response is usually "when it's finished."
That brings up another point. One thing that I have noticed about a few (not the majority) of "import, honda, whatever" drivers is that they want the big power boost, but they don't understand what it takes to get there; i.e. cost. There are compromises that need to be made, and just slapping on bolt ons aren't going to give you a lot of power on an H22. The modifications need to be done to compliment each other to realize the full power potential.
You don't have to feel sorry for us, there is no need to. Parts and modifications are out there, Prelude owners just need to know where to look, and be willing to pay for quality.
Just one question for you. What constitutes NA awesomeness?

------------------
Billy
North Texas Prelude Owners Group
www.ntpog.org