Ok, I'm a tuner on a very tight budget. I want to upgrade my exhaust. What I'm looking for : 1- Low, low price 2- Good sound, not to loud 3- Power gain 4- Looks (don't want an angled exhaust, I want it straight)

Witch would you pick between :

Apexi N1 muffler

HKS muffler

Thermal rear-section

RACtive rear-section

Matrix rear-section

Powercore rear-section

Please help me decide !!