TWF barbs are uber and much closer/ahead of 2HF than anyone would care to admit. Not having to twitch gives very consistent dps.
I suggest 18 barb / 2 rogue or 18 barb/2 fighter with khopesh. The splash gives haste boost and potentially umd (don't laugh -- it's great for buffing, rezzing, teleporting, d-dooring, etc!), open locks, and sneak attack damage. Not using khopesh will drop you quite a bit, but at least you with greensteels will still be above the non-epic barbarians.
If you can, getting a barbarian past life is highly recommended right now for the way it is currently functiong. So, to fit it in, I would do 18 barb / 2 fighter and use your two additional feats on past life: barbarian and stunning blow.
Example half-orc barbarian 18 / rogue 2: 2wf, i2wf, g2wf, improved critical: slashing, khopesh, power attack, and cleave
Example half-orc barbarian 18 / fighter 2: stunning blow, power attack, past life: barbarian, 2wf, i2wf, g2wf, improved critical: slashing, khopesh, and cleave
Just as a basic idea of what you'd be going for,
here is an example. I'd be happy to give any more build breakdown if you care. And, since I see that you're on our server... you could always run us for a couple of epics if that would help =)