Peter,
The rear brace is something you have to set up yourself. There will be no pre-installed brackets attached to the fuse side when you get the model. Having put both Q80 and an Advance in composite fuselages, there should be no problem putting an Advance in this model. It will fit easier than the Q80. If you get a Griffin, I suggest you get on here and ask for motor mounting templates. Also F3a has aluminum mounting brackets for the Advance that should work well.
John