I've seen flexed and cracked fibreglass wings., go for steel wings, fibre glass is definitely second best.
Or better even still, repair the wings you have, well worth it if they are original panels. The rot can be cut away at the rear of the wing and new metal fabricated and carefully butt welded in. I have done a number now and after a skim of filler and paint you cannot tell the difference between repaired and new wing.
Interesting, I think I will have ago at repairing them 1st and then when I can afford new or F/G wings I will, Now where is the best place to buy the wings??