Your design looks smart but is the 7% symmetrical section used on any other successful pattern model? Most of the designs I have looked at ( admittedly in the smaller 40 size or 57 inch span types) have something like a 12 to 15% section. 60 size models also seem similar.
For example the 56inch 40 size ? Sonas? design by Alisdair Sutherland - a free plan in the August 2002 RC Model World (Traplet Publications) -uses a NACA 64A015 root rib tapering to NACA 0012 tip rib. A separate article in the same issue explains why a thinner tip rib is desirable. Basically to avoid tip stall by having a blunter LE at the tip.
The few larger designs I have seen plans for seem to use something that looks like the NACA 64A015 as well.

Check out the airfoil section the experts use for, your first design, unless you want to experiment. Of course unconventional might give you a winner, but can you make it strong enough with such a thin section? Will the wing joiner tubes fit?