Why not just make more wings, and maybe more fuselages.
Just see to that you can mix and match all as you please.
I have cut a set of foam wings with a different airfoil, Eppler 197, and taper.
Increased the WS to about 78". Haven't got any further yet.
One thing about the Hog: it's a very nice platform for experimenting.
Next step is of course retracts.