You can also use a "street tuner" for delete purposes . I actually saw one for sale yesterday and the guy was asking $750 shipped I believe.
Personally I would go that route. Ryan has dones some pretty awesome stuff with their tuning recently, which I think should be released for the 4th gen guys very shortly. The Overdrive software IMO is a must have. It's the same tuning that RevMax uses on their transmissions...That alone makes a world of difference. I haven't had a chance to hand calculate very much, but my fuel economy is up by about 1mpg over the old H&S tuning..others have reported a little more.
What has to be done to a street tuner to make it work with deletes?