SS is an excellent choice with WP. War Mace is also a fine choice (more AOEs). Stone is good (high single target damage). From a casual player point of view I don't think you could really go wrong with any of the secondaries though.
Agro shouldn't be a concern. Just remember to take Taunt at some point if you're grouping a lot. WP does have a taunt aura but you'll find that taunt auras are a bit overly discussed on these boards and not as meaningful in game (unless you plan on making Ham sandwiches while your team fights). My WP/Stone Tanker (one AOE) has no problems at all holding agro.
I'm not going to say much except go with Super Strength.
Trust me, you will love it once you hit level 38.
As far as agro concerns...take Taunt when you can for when it gets tough.
I apologize right off the bat because I am more than certain that these posts have been on this board more than enough. But I have been thinking about making an Willpower tanker and I wanted to know about them and if they are sturdy, also I wanted to know what a good secondary is with this spec, I was thinking SS but I am not sure. Also, if any of u guys have some tips, or tricks on this spec that would rock! Thanks for your help.
ps. I plan on just doing casual play with this character. Running missions with another 7, not so much end game material.
pps. What is the best way to hold aggro with such a build if there is no AoE within willpower?
Sorry for the noobie questions. Thank you all for your help!!