Earth Genasi, AC Barbarian with 17/- DR

[Sun Wukong]

I would go for a Barbarian 20/Fighter 10 build. It will mean -2 points of AC because you cannot really spend more than 10 points in Tumble, but as Valefort said earlier your non-rage AC will remain rather high regardless.

Now, as for the perks of this change, you gain access to fighter bonus feats and proficiencies for free. Pre-epic, you can spend your fighter bonus feats on some of the feats you have on your build and instead acquire some of the much needed Extend Rage feats. On Epic levels, you can use those figther bonus feats to pick up epic feats such as: Epic Prowess, Epic Toughness, Armor Skin, and most importantly Epic Damage Reduction.

As for the topic of DR:

• Barbarian 20/Fighter 10 DR = 15... 5 (Base) + 1 (Greater REsilience) + 9 (Epic Damage Reduction)
• Barbarian 22/Fighter 8 DR = 16... 6 (Base) + 1 (Greater REsilience) + 9 (Epic Damage Reduction)
• Barbarian 26/Fighter 4 DR = 17... 7 (Base) + 1 (Greater REsilience) + 9 (Epic Damage Reduction)

Thus mechanically speaking, I think you would be better off with slightly less DR. 15 is still quite a lot and you could spend the spare fighter bonus feats on Epic Toughness or something to get +30 HP per feat.