The way I see it, the simplest and easiest solution to that problem would be, as you say, build another wing.

As its a kit you'll have plans I presume, as the wing will be built over them. Just be sure that when you first build it, you trace out the wing rib pattern and anything else that you might need to replicate the wing.

Then the 2nd time around just build the wing straight (no polyhedral) with less dihedral and with ailerons.

If you need a little extra power, upgrading to an 8 cell pack should give some extra RPM on the motor without having to upgrade the rest of the power system.