Gordan came up with a neat system that we've been using on his Tony, Pathfinder L.E., and others. It uses a horizontally grained, notched trailing edge, shear web as part of the jigging system. It's shown on the PF L.E., and Tony plans. It uses a rib tab just aft of the spar slot, and by using them both as parts of the jigging system, will build a wing as straight as your building surface.
It's possible to frame up the wing, install the top and bottom spars, controls, leading, trailing, and center sheeting, while still jigged up. The wing comes out straight, and strong.
Several who have used this system have been impressed with the results.