My brother matches your stats closely and rode my 158 Templar. He didn't have any issues with a 10.5 boot. I'm only 5'7 but around 175 and the more i ride the board the more i like it. The larger board you go to the harder its going to be for you to maneuver. Also your angles will have a little to do with your boots fitting. I don't think it would really be an issue.
As far as the board, i like it in the icy crap we normally get in the north east. On fresh pow days i have trouble but that's just due to my lack of experience on fresh deepish snow.