Just to be clear, the price is NOT a case of beer etc right now. I was referring to my old vehicles (eg 2000 Trans Am) where pricing wasn't bad because the ECM was unlocked. There is ONE company that can handle this, HP Tuners. They are based out of Buffalo Grove IL
https://www.hptuners.com/
It's going to cost you over a grand to unlock the ECM. Then, you will need to pick a speed shop to do your tuning. I have used Speed Inc (https://www.speedinc.com/) for my tuning in the past but not sure how good they are with these new rigs