I was starting to look around for a catback exhuast for my car, i had a couple of questions that i wanted ask people who have a better understanding of catbacks

how big of piping should i go to get if i plan on doing a n/a setup?

i wanted the exhaust tip to leave my car at an angle, so do i get that?

also, is there a noticable difference in using a regular catback or gettin a straight pipe?