I don't know of anyone around Houston, but there is a guy on here named Slade who does stuff like this. I believe he's in the DFW area though... don't know if he'd meet you in Houston or not. It might be worth asking him. Also, I believe Clark Reehm does on the water tuning. If anyone would be willing to travel, it'd be Clark. I guarantee you he'd meet you at Toledo Bend or San Rayburn. And lastly, I don't know if you've watched it, but Ben Parker has an awesome video on how to tune your Lowrance units. It's fairly basic settings but it definitely points you in the right direction. It's definitely worth the watch. Wish I could help you more.
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." - Doug Larson