Rookie questions

Hey all...I have a few questions for you.
My buddy wants to do a few things to his 99 2.4L Cav so I'll fire off all of our questions.
1. What size catback are you guys running? Best muffler (not too loud!)?
2. What is the best intake?
3. What is the best lowering set up? I had Eibachs in my 97 that I loved...however, because there were no options for struts at that time, the pogo (rebound) was terrible.

Obviously I've asked a lot of personal choice questions but all of your input is appreciated!

Also, I haven't found a lot of places to purchase parts, any links you have are helpful too.

Thanks in advance for you replies.
Rob
04 Comp G

2.25 is the biggest you should go with that. Their really isnt a best muffler, its all up to personal preference. Pretty much all intakes are the same, give 7-10 HP. Cold air and Warm Air are the same as well.

go a.e.m. on the intake, and like before 2 and a 1/4 is the largest with out complications, go borla for the cat back. borla is the shit

I have a full 2.5 inch exaust from my down pipe back and i absolutly love it, didnt hinder performance at all as you can see by my quarter time. Also if you wanted to upgrade to forced induction or NOS in the future 2.5 is def the way to go.

Good info...thanks guys.
Any insight on the suspension?