I'd use my 5 points on this:
Catalytic converter deletion, 1 point
Cat back exhaust, 2 points (
will a single exhaust cost you more points?)
Header, 2 points
Look into the Rtek chip (PM ROEN on here since he has more experience with it) for tunability while maintaining the "stock ECU"
Roen has made as much as 170RWHP out of his NA so you should shoot him a PM and see if he can help you out a bit more.
ENDER: I'm interested to see the dyno results after you tune it. Were you able to get the gasket in time for the dyno?