Your BEST bet would be to get a TRUE cold air system. They provide the BEST HP/TQ increase and are the best foundation for future performance mods. I decided on VARARAM and it works fantastic. Its supporting 450RWHP without any issues.
Your NOT going to see GOBs of new HP. You may see 10-12 on a good day with JUST a cold air intake.
Before you install your new cold air intake, find someone that can data log your engine. Anybody that has HP Tuners OR EFI Live can do it for you. Some scanners have live sensor monitoring capability and they can show you O2 sensor data and STFT & LTFT
Examine the Long Term Fuel Trims (LTFTs) and see where they are averaging. They "SHOULD" be near ZERO or slightly negative. When you install that new cold air intake, re-examine them. If there a lot more positive, you can benefit from tuning. If you add your new cold air intake and get a decent tune, you will see more HP/TQ and better fuel economy.
Excessively Positive LTFT will cause your Wide Open Throttle Power Enrichment (PE) AFRs to be excessively rich and that results in a power LOSS at WOT.
BC