Agility will help with your Defense, which is great for a WP tank, it will also boost your recharge and END mod, and you have a few powers that can make use of that boost (stamina, physical perfection, possibly conserve power if you take that to open up physical perfection). I would think that would be enough to keep you from running out of endurance.
I would not think that a Cardiac alpha would be as advantageous to you as the Agility. But you might also consider a Musculature alpha. The damage boost might be nice to have, and it will also give some end mod boost as well. Not saying that it your best option, but it is something to consider.
Ok, so I made a Willpower/Titan Weapons Tank. I seem to be constantly chugging at 37. I plan on going with Energy Mastery and picking up the Physical Perfection power. So, with 3 +recovery powers (Stamina, Quick Recovery, and Physical Perfection), should I go with Agility or stick with Cardiac to help with end issues? And this is all before I've bothered getting IOed up. Thanks for any replies.
Shadowblaze - Lvl 50 Dark/Thermal Cor, Alexander Kalsoa - Lvl 50 BS/Regen Scrapper, and a whole bunch of other Alts. Global is @Shadowblaze.