Surfing Waves

Hi all, I am going to be shaping my first board, a retro fish. I am 5'11" and 160 lbs. Some people say to ride a twin fin fish a lot shorter and some say a just 1 or 2 inches shorter than my shortboard. I surf in New Jersey which does not get big too often. I want something that is easy to paddle into waves and still responsive. Would a 5'8" be a good size?

I'm pretty sure they say ride a baord 1-2 icnhes shorter than your usual shortboard. I'm 5'9 and I'm looking to get a 6ft retro twinny.