I am very pleased with where I mounted mine after 18 hours of flying so far. I centered the radio stack on the panel with the PAR100EX on top since it has a short tray. I measured carefully and positioned it just under the center rib.
Are those Dynon mains?
Mike, how about the remote mounted comm box, did you mount it to the sub panel, stick it in the tail, etc? And how's it working for you?
I like what flyguy did, that seems to make the most sense right now.