you won't be sorry you bought HP Tuners. It's a good program. Not perfect, but plenty good.
Spend a little time building a good Speed Density Tuning template for the scanner, then get a wideband O2 and you'll be off and running.
A year after swapping mine I'm still changing shift points and converter lockup points, playing with throttle cracker, adding electric fans, and on and on.
You won't be sorry you bought it.
I do recommend getting the LS Droid app for your phone. If nothing else it will let you recover a bricked processor, or even clone your PCM if it ever goes bad. If you clone it, you won't have to pay HP Tuners for another license fee when you replace it.
Joe