I would like to deck my 14' V-Hull. This forum has alot of great pictures, ideas. I just don't what size wood and plywood to use for the deck. Need some help. Thanks....

2x2's will do it for the framing and 3/4 inch plywood for the actual deck. Make sure you use water treatment on all wood beofre you install for good or put carpet on it.

I used 1/2" on my boat. with zero flexing issues.  I have aluminum supports, but 2x2's should work well