The transmission will be a 4l60e.
Thanks for the replies and the personal experience, I have not decided which route I will take.
To respond to the PCM question, I did get the PCM out of the truck.
I will more than likely have them reflash the PCM with their performance tune, I'm just not sure about the other options at this time.
I plan to do more research and come to a conclusion in the near future.
It is not all about spending the money on the harness, to me it is more about doing it myself and feeling like I have accomplished something. I guess that is the engineer in me.

Thanks again for the advice and opinions....