For security what's the best option, 1. A well secured 'up and over' (large centre bolt at the bottom, staple and hasp buried in concrete padlocked to the bottom corners and the whole door reinforced with 2x4 lengths of wood, or 2. A roller shutter door. Sources for suitable 6'6" x 7' doors would be appreciated. Electric motors and keyless entry isn't an option I fancy.