As long as you're not looking to charge big lines, 156 should be fine and could actually be more fun if you're primarily looking to jib around. If you get into going fast and hitting the steeps, you'll probably want something a little longer. I'm a similar weight to you (195 Lbs) and ride a 161.5 cm board (2010 TRice C2BTX w/ HP) and I'd consider that on the shorter side for what I should be on, but I'm willing to deal with a little shorter effective edge in exchange for quick turning in the trees. I also have magne traction, which I think helps you downsize without losing edge hold in less optimal conditions. Also if you think you're going to be riding deep powder, additional length is helpful. But overall, it sounds like the board should work out great for you and I think it's really awesome that you're getting the whole family out there!