The Type-25 was a limited edition produced by Iain Litchfield, originally based on the Blobeye, then gradually improved until the ultimate (until the next one!) Hawkeye with Cosworth engine. Early Blobeyes Had pretty standard internals, but by the time of the MY05 cars they had forged pistons. These were generally 350bhp/350ftlbs, but mine (build no. 27) has just given 350/385 following new head gaskets (which it seems all 2.5 motors need around 30,000 miles).
My guess is that for your money you should be looking at a Cosworth version (that is the 415 or more bhp model), although I believe there are a maximum of only around 15 in existence, and that's if they all still survive!
Fifth Gear did an article on it
Ordering from new you could choose any base model you wanted, so they are not all based on the Spec C. Mine is based on the standard JDM car, as I'm old and I wanted some creature comforts!
Any questions, let me know.