length depends on what you ride and personal preference more than anything else, with height being a very minor factor and weight can be a factor if you are quite heavy or quite light. 90% of all mens boards are between 152 and 162, so thats only a 10 cm difference over a huge weight range (a normal adult can be anything from 140 to 200 plus pounds)
not knowing anything else i thnk most people would agree a good do anything size for you would be 157-159
but thats not written in stone, its not like you couldn't manage with a 56 or a 61 depending on the board.
the good news its hard to really fuck up a board purchase, looking past all the marketing nonsense almost every snowboard is capable of doing whatever riding you like
boots are the most crucial part, definitely read the bootfitting stickies at the top of the forums