If it makes you feel any better, I had similar concerns when I bought my board earlier this year. I'm about 5cm shorter, several pounds lighter, went with the 151 and regret it. I definitely wish I got a longer board.
edit: I swapped boards with a friend for a run, he had a 155 and it felt pretty good (aside from the fact that his board was too wide for my feet). If you don't plan to be hitting up the park, I don't think you'll have any issues.
Last edited by unsunken; 01-01-2010 at 09:18 AM.