Don't get too hung up on the HP#. Most claims you'll see out there are grossly overstated. You opened up your exhaust, now open up the "other end" with an intake. Those two mods go hand in hand. The chip/flasher ties them together nicely. I have all three mods, and my chip is out for reprogramming right now. While my Ex still feels great, being without the chip is very noticeable. As the others have said, get a SCT based chip/flasher and get Doug and/or Wayne to write a custom tune for you based on your mods and planned mods, driving style etc.
You won't regret it. There are hundreds of discussion threads on this very topic. Check the archives using the SEARCH function on the site to see what I mean.