A mild tune might be in order. Would probably serve you better to do a CAI, full Headers (Speed Daddy from Ebay, work well at $200), and then HV3 with a tune. Then consider maybe a cam, rockers, depending on your preference possibly some tranny work, shift kits and what not...
Without going the boosted way theres not alot to do with these to make power. Turbos make more power but take alot more work than a top swap goes, unless you have a machinist/mechanic cousin with a shop, and another DD for a couple weeks... then turbo away