http://www.corral.net
is another good one.
The DOHC responds extremely well to blowers. Its not hard to see 400 rwhp with 8 lbs of boost. The T-45 tends to have weak syncros, so a shifter with positive stops is a good idea, but they do seem to hold up to the power pretty well.
Is this car going to be a street car, ocational strip/track car, or is it going to be track car? If its going to be a street car, then air to air cooler would work better then the Vortech air-water after cooler. The water heats up pretty quickly.
Cobras also really like gears. 4.10s or 4.30s are the most popular.
What sorts of specs are you looking for?