DW is best. Even higher ilvl doesn't guarantee that 2H would be better option so I would suggest to sim possible upgrades. For example I got couple weeks ago 226 polearm as a choice from vault but replacing 226/216 DW with it would have been around -100 dps.
Monks (ww and brm) have a "secret" passive, that buffs your damage when using a 2-hander, however this buff still isn't enough to make 2-handers better as you can use 2 enchants with dw. I'd consider taking 2-handers only if the ilvl difference was 10+ ilvls