My advice would be to find a shop that has a reputation for bullet proofing them and getting it done. You'll keep dumping money into it otherwise. You'll have a good setup that performs well and is reliable if you do.
Edit: This may very well be what you are talking about doing- just couldn't tell. I don't know who does this in the DFW area, though.
I've heard the term "bullet proofing" used before. Exactly what does that consist of?
I've deleted my truck in the sig and haven't had any issues with it since. Egr and cooler delete, DPF, Nox and Cat all gone. I did have to have ARP headstuds installed because I was running a hotter tune than I should have towing my 5th wheel. That was using a Smarty tuner. I switched to EFI live tuning with a tuned Transmission Control Module from Draconian Diesel. I run on 35" tires and towing the boat I average about 16mpg. Empty I average about 18.5. All hand calculated for you naysayers. Worth every penny, especially because I love my truck so much.
To the OP, Diesel Pros in Hurst does excellent work. I would say they specialize in Fords more than the others even though they do and will work on Dodge and Chevy. They are off of East Loop 820 at Hurst Blvd/SH 10. That's who I recommend.