If memory serves. Mace of the Shadowed Soul. But training is pointless anyway, as you can train as you fight, unless you get waaay behind then it's an annoying few hours to catch up.
http://wiki.project1999.com/Mace_of_the_Shadowed_Soul Good 1hd Blunt here.
Slam stuns like bash, but does less damage. I think to ultimately answer your question, if you want to do the max damage as a Tank, then stick to 2hd weapons and use slam.