You can't make a Shield/Titan Weapon character, so if you decide to go Titan, then you're got one less armor to consider.
You're picked three of the best armor sets in the game. Invulnerability and Shield are hybrid defense/resistance sets, while Radiation relies mostly on resistance and regen/absorb.
Titan Weapon is a decent choice, if you can put up with the "momentum" mechanic. Radiation is a good choice, though a bit endurance heavy, if you want to go Radiation Melee, I'd probably pick radiation armor to offset the end cost (Radiation Armor has Gamma Boost, which increases endurance recovery). Mace is the most straightforward set in your list, again, a decent contender.