Randy -
I'd try cams and a good dyno tune. I don't know if anyone makes a flash tuner for this, or if someone is doing dyno tuning on them, but that's the logical next step. Tweaking the fuel curve and messing with spark can yield a lot of power on a computer controlled car. Flash tuners are useful, but they are pretty generic by nature. You might go to the Hot Rod forums and PM Dieselgeek. He's the EFI guru who did the set-up on the Maverick that they blew up at LACR in the last issue of HR. He's a pretty sharp hombre and a nice guy (he's been to Maxton and hangs with Keith, so he knows what we do). He REALLY knows what you can accomplish thru the computer.
For cams - don't know who is making them, but try Delta Cams in the Pacific Northwest. They do LOTS of Subies, Mitsus, etc, and may have something for yours. And they're CHEAP! Overhead cams are generally not TOO hard to swap, but I don't know on your engine. If you need a hand, give me a call (see the ECTA website).
Good luck - look for you in October.
Dan