I would give Electric Armor a shot. You can eventually ignore Endurance Drain entirely, you also get some recharge in the form of Lightning Reflexes, and Energize will also reduce the cost of your endurance powers for half a minute. Power Sink is perfect for getting back any lost endurance since Titan Weapons eat a lot of endurance. Plus you have the resistance to recharge debuffs and psi resistance too. Edit: When I say you can eventually ignore Endurance Drain entirely, I mean by level 8. By then Grounded and Static Shield will offer a combined 110% or so resistance to Endurance Drain, never fear those Elec blast mobs/Sappers again.