Anything but the lightest power armor will increase your size, and thus give enemies a +10% to hit you, for only a very small amount of increased armor. Armor stacking past a certain point is basically pointless, you can render yourself immune to small arms fire but anyone who wants to hurt you<em>will</em>be able to, it will just be slightly more annoying on their part to have to get armor piercing weapons.<br/><br/>There are heavy man portable weapons, but none of them actually require a strength score or test to use.