Gearing for hp doesn't matter if you don't get hit. A number of spells also will lower your AC and may be worth using (armor, sheen of stone, all the shifter lesser defensive enlivens.) Use the officials item search to find a ton of more useful -ac gear pieces. Remember you get wands and what not too which can get you these spells when you are not the right class to cast them.

As a melee, I always gear for -ac for defense perfection at 15. It will make your life so much easier!