Foam to fiberglass glue

I had a leak and water accumulated under one side of the Bigfoot, in the overhang, over the side walls of the truck box.

The foam is saturated with water and the plywood backing panels for the tie downs are rotten.

So, I have removed all of the kitchenette and floor. I have taken out the furnace and water heater.

I need to replace the foam and the plywood backing panels.

My question is what is the best glue to fix the foam to the fiberglass. I am also thinking of blue foam over Styrofoam.

I still have to find the leak before I close it back in.

Bob