Apexi drop in filter and any brand inlet tube.
Catback if you want louder than stock get a Invidia N1 but that thing is LOUD.
Get a Invidia Q300 if you're looking to get a header down the road.
Greddy SP catback is another one you could get for about $155.00 more than your budget for a catback. Or save up and buy a Perrin 2.5 resonated catback that way when you add a header it won't be LOUD.
Join up with your local FT86 club and attend a club meet that way you can hear different catback exhausts.
That will help you decide what you want.
Just my 2 cents!
