Obviously 2ACP. Hellplate is just an ordinary MW Full Plate armor with cool name. IT costs 2000. Mithril as material for crafting heavy armor costs 9000. so you get armor with 2 ACP 3 MAX DEX and 9 AC fo 11000. With class skills of hellknight and fighter lvls(if you were one) it stacks up to 0 ACP and over 9000 MAX DEX.
other problem is roleplaying. Shiny silverish armor is not so good at intimidating foes with your HELLISH powers)
