What happened to your me-110? Lose an engine? Why not just acquire another me-110. I love mine...flies awesome....but mine has more power then your two 20cc motors are providing.
If you don't want to replace the me-110, how about an F7 tigercat. Your two 20cc motors should power that one easily as the wingspan is smaller at 82.9"
http://www.troybuiltmodels.com/items/ESMF7F-83BAF.html