Warforged and monks are terribly non-synergystic. Just as the warforged's armored skin impedes spellcasting, so does it impedes any monk ability reliant upon being unarmored. That's not to say that warforged would be terrible monks, just that they would be different. As a warforged monk, I might take the UA variant that trades away movement for DR, and I would certainly focus on getting that "one good hit" as opposed to multiple attacks. Two ways to take the warforged monk that would work: the "Stunning Fist Guy" and the "Grappler."

The Stunning Fist Guy has a high Str and Wis and takes feats such as Ability Focus (stunning fist), Extra Stunning, Pain Touch, and Falling Star Strike. He's all about disabling opponents rather than hurting them. He's a fine partner in a group that already has damage output from other classes such as the fighter and the wizard, and he makes a fantastic duo with a rogue.

The Grappler is all about choking people into unconsciousness. I won't go into this one because everyone's well familiar with this monk feat path. I think that a warforged monk would be quite good at this. He might also consider taking this archetype as a fighter with an eye on the reaping mauler PrC.

With either of those monk archtypes, a warforged monk would benefit greatly from taking one level in fighter and simply wearing armor (or taking Adamantine Body as a feat). You're already severely penalized for your armored skin, so why not make it the best armor it can be?

I've given this race/class combo a lot of thought.

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