There are some options listed in the Unearthed Arcana such as Totems, but I dont have the source handy. However another suggestion could be:
Combat Style (Ex): Similar to a Ranger's virtual feats except as follows. The benefits of the barbarians’s chosen style apply only when he wears light, medium or no armor. He loses all benefits of his combat style when wearing heavy armor or carrying a heavy load.
(NOTE: This could be expanded into many various styles based on culture.)
3rd: A barbarian must select one of the following combat styles to pursue: hunter or warrior.
Berserker: Powerful Charge (MH)
Hunter: Rapid Shot
Nomadic (Melee): Mounted Combat
Nomadic (Ranged): Mounted Combat
Warrior: Power Attack
9th
Berserker: Greater Powerful Charge (MH)
Hunter: Sharp-Shooting (CW)
Nomadic (Melee): Ride-by Attack
Nomadic (Ranged): Mounted Archery
Warrior: Cleave
15th
Berserker: Hurling Charge or Reckless Charge(MH)
Hunter: Shot on the Run
Nomadic (Melee): Spirited Charge
Nomadic (Ranged): Improved Mounted Archery (CW)
Warrior: Great Cleave
(CW) - Complete Warrior
(MH) - Minitaures Handbook
Or simple a Bonus Feat at 3 levels with a specified list of feats, perhaps some of the Rage feats (CW) as options: Destructive Rage, Extend Rage, Extra Rage, etc.
Just a few thoughts off the top of my head. YMMV
