Hope you don't mind my 2 cents.
2 main questions come to my mind:
1. Your skill level
2. Your predominant wind level.
You said above that our main wind speed is 15-25 mph. Then you said mainly light wind sailing. 15 mph would be light wind, but 25 mph is not light wind.
I would suggest that if you want to sail mainly light wind sailing (15knots & less) then the big board route makes sense. If your sailing is mainly 15+ knots on coastal conditions, a smaller board like Roger suggests makes sense (then maybe fix the old board for the odd light wind day).
Your sail size range suggests a smaller board. If your sailing >15knots a smaller board will be much easier and more fun, though you should be waterstarting.
Last edited by mike; 10th May 2008 at 10:40 PM.