I'd suggest /Dark or /Rad because both have a self-heal that fills in the gap that Shield lacks. /Dark is a 100% chance to heal on hit, while /Rad relies on the "Contaminated" effect to heal, but you get that pretty reliably. /Rad *probably* has better AoE than /Dark, but I haven't played too much with the new "Touch of Fear" so I don't know.
If you go weapon, /Mace is a good choice, but so is /Broadsword. /BS has Parry, which is nice because it increases your melee defense, making it easier to hit the cap.
/Martial Arts is another good choice because Storm Kick gives +def to everything, meaning its even easier to hit the def cap. The only downside with MA is that it only has 1 AoE attack.