welcome to the club! I'm sure you'll have a blast with your car. I've got a '93 USDM R1, and it's a blast to drive. Essentially i've got all the mods that you're wanting to run. The car is stupid quick and responsive. I'm going to be doing suspension refreshment this spring to prep for the next autocrossing season.
if you're going to open up the intake and exhaust, unless you're eventually going single turbo, you'll probably want to have someone enlarge the wastegate on the stock twins. Mine hasn't been done, and it's running about 14lbs of boost. The stock wastegate seems to be unable to regulate it to less than that. I imagine things are just flowing too well. I don't expect my turbos to last too long at that boost level. Since i'm eventually planning a modestly sized single, i'm not going to be too broken-hearted when they finally pop.
I'd also recommend paying for tuning from a reputable rotary tuner, unless you're experienced. I'm not, so i paid for a tune. I'd rather do that, than have an 'oops' and pop it.
My personal thoughts are, have fun with it, enjoy, but most of all, drive the wheels off the damn thing! Autocrossing has been a ton of fun with that car, and i'm likely going to step up to lapping this summer, now that the nose is stuffed with a fat rad. You won't regret it!
~Matt