What size snowboard is good for me?

A board that is about 155 will adequately accommodate your weight. However, this may be to short for someone as tall as you and lead to a lack of stability. A good rule of thumb is to make sure the board reaches the bottom of your chin (at least) in order to correctly account for your height. Unfortunately, there is no perfect way of telling what board is right for you without actually trying it. I would rent a 155, and then another slightly larger size just to see what you like the most. Also, the longer the board the more control, yet less ease of use. So keep in mind that if your not the most experienced snowboarder it may be useful to start small and then work your way up in the future.