There are several car shops across Thailand that can do this. The two best ones I think are:
ECU Shop - https://www.ecu-shop.com/
Powerlab - https://www.facebook.com/powerlabthailand/
I started off getting 2 piggyback ECUs installed that fit in my glovebox. One controls fuel pressure and boost control, the other is a diesel management system.
It took a few hours to install, then one of the mechanics got me to drive the car while he adjusted the tune to suit my driving style. What we found was it was making too much power and the clutch was starting to slip. So he detuned it a bit until I went back a few months later and fitted an upgraded clutch.
The boost controller has 3 power settings, the dms computer has 2. Even on the lowest settings it's like a completely different car to drive. Overtaking is much easier and faster. Throttle response is much better.
I got mine done at Powerlab, but ECU Shop would be just as good I think. The customer service I've had at Powerlab has been great, they really go out of their way to make sure you're happy.