I agree with Jille. Ideally I would be looking at an 11m but within this situation I have an opportunity at 2 good deals on second hand sails so price is a consideration.
I have to admit I'm not that familiar with the concept of light wind slalom vs high wind formula sails. Does that mean that the light wind slalom 9.9 would have better low end grunt and early planing but lack upper range stability over the high wind formula 10m?
Kvda - just broke the combination you're recommending. Would rather not go there again.
My next size down is a GTX 8.5
Thanks for all the great advice and insight. Keep it coming.