If you sign up on honda-tech you get a 10% discount from IP. Just wait for a group buy if you really want to get a good deal. As for turbo sizing, the t3/t4 combo is really an all out drag turbo. Its about as large as you really want to go but with that you also get lag. A 3'' downpipe and exhaust will help spool faster but there will still be a very noticable amount of lag. Its all just preference. Do you want a fast spool up or high end power?