hEX Interlink

I have purchased two hEX routerboard devices and am looking to have them be load-balancers between two links. I was told what I am looking to do is very easy but am having issues with trying to get it setup.
The inter-link connections are a 100mb vdsl line and a ethernet over power “gigabit” adapter. I need the interlinks to hand off vlan tagging to the switches as a pass through device.
I would like to have port 1 on both of the units be the back-haul to the switches on both sides. Port 5 be the gig Eop adapter, and port 4 be the vdsl. I need them weighted more for the gig connection than the DSL, but if I loose power I need fail-over to the DSL as the Eop’s don’t work without power.
Any help is greatly appreciated.