[kruptos]

At my ISP we offer XGSPON/GPON and we have to use our equipment for the ONT (In our case Adtran). We have adtran specific handshake stuff that we have to manage. Your ISP might offer to just use their ONT and put it in bridged mode so you can use your own router/ap.

There are ONT SFPs that contain everything you need to connect back to the OLT. Maybe you can ask your ISP if that is supported?