I have had this guy tune my 09 Pontiac G8 and when I got the GMC truck, he did an upgrade to it also. He does a lot of GM computer stuff (gas or diesel) and will build you a wiring harness for a computer for a lot less than the market has them. He is big into 6.0 liter engines and installing them into older vehicles. Talk to him and see if you would be interested in what he does. He works out at Forbes field during the week, but has every other Friday off and his weekends are usually available.
However, if I were going to go to Texas, I think I would go down to Patrick G's place and let them have their way with the computer.
http://guerragroup.com/LSXDYNO.htm