The last post is correct I think! It really depends on your ability. I am close to 200 lbs and I ride a 6'4" Channel Islands 19" X 2 3/8 in some waves, but not in all conditions. There is a limit depending on your weight how small and narrow you should go. If you are sitting in the lineup and the water is nearly up to your neck you may need some more float. I also can get by with less board depending on the kind of waves I am riding hollower waves help your board to plane better(ride more on top of the water) smaller mushier waves you may want a wider thicker longer board, or a fish to get your board to come to life a little. Your question is a little more complicated than yes or no, so I hope this helps you. You should try a couple boards out that are close to what you are thinking of buying and see how you do on them. I feel experience will tell you more than we can, as we do not know your surfing ability.
Good Luck!
Tony
http://safaritownsurf.com