I got a 1997 Accord SI and I have already added the following aftermarket parts: AEM cold air intake and Greddy headers & exhaust.

Anyone got any ideas what I should do next. I don't want to get into anything major right now... Everyone at the aftermarket shop I was going to is on crack and messed up everything they did. They cost me too much money to fix what they did so I figured I would do everything I could myself. I've re-done my lights and got new rims I need tires for. What should I upgrade before mounting the rims. ANY IDEAS ON ANYTHING I SHOULD DO?

Also when I punch too hard, actually not really hard at all, rather than easing the gas, it doesn't pick up... it sort of pauses... then it shifts shifts real hard. It's done this before I got my aftermarket parts put on and I took it to the shop thinking it was my trans. They ran it through their machine for $80 and said it was cool... They said, "Every car this year shifts like that." My mom got a 92 and she had the same problem... $80 later they told her the same thing they told me. Is this "hard shifting thing" true and is there anything I can do to prevent this?