I would personally avoid shield/rad. It's a great combo, sure, but it is also very endurance heavy. Mine didn't get endurance under control until incarnates.
As for my recommendations, I want to say Super Strength. Rage (especially if you double stack) brings damage to really good levels, however, Foot Stomp doesn't benefit from Gauntlet's AOE increase, and I personally don't like the rage crash.
A couple of my favorite tanks are Bio/Energy and Bio/Spines. Spines is better for AoE damage while EM is better for ST damage.
I've got an Electric/Electric that is a lot of fun, but the Toxic hole is painful on Apex.
Battle Axe is a good set, especially with Axe Cyclone. however, it is also endurance heavy, so I'd pair it with something that has some endurance management.