As CivicSiRacer said, get a rulebook. You'll save yourself many a headache and heartburn. That said, here's what I remember.

Going with GCs and Konis is fine -- no problem in STS. Header, intake, exhaust are all fine too, as long as you don't muck around with your cat -- that must be OE. If you rebuild the head, then you must stay within stock specs and use stock parts to be STS legal.