Feat suggestions from non-core books?

[Darklone]

isn't that a feature of 3.11ed power attack now?

Nope. Power Attack 3.5 gives you a bonus of twice the penalty you take on your to hit roll. That Twohanded power thingy is IIRC from Quint Fighter and gives you twice your strength mod instead of the usualy 1.5 times on your damage bonus to weapons.

Strength 24 Halforc raging with greatsword: 2d6+14 instead of 2d6+10. Ugly at higher levels.