I have Trigorilla Pro printer too. I`ve bought full set of Trigorilla 8 bit version hardware, want to make downgrade. I bought it all in Aliexpress Anycubic Official Store. I have contact to Anycubic support via Skype to the person Anycubic-Renee. He help me with all hardware. If you will expect some problems with support, I can sell you my Trigorilla Pro mainboard after downgrading my printer.