For a 10.5 boot you should be fine without going to a wide board, as long as you ride a little angle on your bindings. If you ride bulkier boots, that could be a different story, but I would the not wide version myself. As far as which size, that depends more on what you're doing and where you're riding. If you're going to spend most of your time hitting rails and what not, go with the 152. If you live out west and want a board that will be fun if you get some fresh snow, go with the 155. Both sizes will be a fine size for you and work well for park riding, it just depends if you need something more versatile.