I plan on doing the exact same thing when I get home from the war. I'll have plenty of cash to play with. I might save it till I'm out of the Corps for good though, because I want to get a cleaner rex when I get back to Albany. If you have the money, I'd go with a Type-R (B18C5). That's 200 hp right off the bat. With all the aspects you're planning on customizing, you'll jump 300 hp easy. Remember, there's no rush when working on a swap or anything else for that matter. You're going to get frustrated at times, it's a given. But if you put time into it the results are pretty rewarding. Good luck man.