resistances doesn't stack, just immunities. so it'll be 50% imm 10 resist with both armor/shield affecting the same weapon type.
you can switch types (heavy flail, greataxe), and they'd only have the shield count. granted though, they can do the same to you (switch weapons) and ignore your resistances.
but there's some nice two handers out there (mention above, has vorpal on that axe i heard). also, with keen 2 handers, your crits would really rock them (wm levels

)
atm, i'd suggest going with heavy flail for improv crit as i havent seen any decent blunt resist armors (so you just have the shield to worry about)
still, there's some content coming in, so we don't know whats in store yet (sunken isle, frostdale)
usually, when im building a fighter, i choose to focus in 1 single hand, and 1 two hander. (still carry around a whole variety of weapons though)
when i come across a fighter type, it's usually the single hander i use.......but when it's a mage/druid/rogue, whip out the 2 hander
