Why don't you save all that money and get the nsport turbo kit? Best bang for your buck at $3500
If you don't want to go that route, first thing I'd do is get rid of those darn bosch plugs and use ngks!!!!!
You can also replace your crank pulley with an unorthodox one or an ASP one. Also replace your stock fan with an electric setup.After that's done and your still not satisfied with your engine response/power, then get some cams and an ecu upgrade, or exhaust headers.