...However none of them match my ecu, and I don't want to brick it right from the start...
purchase a spare ecu
build a bench setup (inexpensive and easy to do)
learn and understand using the various software available on this site (the stickies are all you need)
At some point, you will likely encounter a bad flash that will require bootmode recovery. It's better to learn learn the process and its foibles on a spare ECU.
-Cyril