to make the armor thing, you need despencers, redstone, armor, an activator (i.e. a lever) and blocks to build. first, you put 4 dispensers down, 2 stacked on each side. like this--> [ ]
next, you put a block next to each bottom one, and lace it with redstone. put an activator at an area where it all connects. put one armor in each dispenser.