Barbarians, Favored Souls, Paladins, Fighters, and (if I recall correctly, though it's not listed in the compendium) Monks all get class-based Toughness enhancements on top of the "Racial Toughness" line of action point enhancements.

While the "+10 HP" with Warchanter II (as mentioned in this post) goes a little bit of the way to offsetting the fact that a Warchanter will essentially be a bard in melee, with just about no exceptions, I don't believe it goes far enough. Bards only have a d6 hit die and, unlike rogues, no Evasion/Improved Evasion, so it only seems natural that Warchanters should have access to some extra toughness enhancement, later than other classes, but still available. Based on the class-based ones, I would place them something like:

War Chanter Toughness I
Prereqs: Toughness, Bard level 6, Points spent: 20, Bard War Chanter I
Cost: 1 AP
Benefit: Grants you 10 additional hit points if you have the Toughness feat.

War Chanter Toughness II
Prereqs: War Chanter Toughness I, Bard level 9, Points Spent: 30
Cost: 2 AP
Benefit: Grants you 10 additional hit points if you have the Toughness feat, bringing the total increase to 20 hit points.

War Chanter Toughness III
Prereqs: Bard War Chanter II, War Chanter Toughness II, Bard Level 12, Points Spent: 44
Cost: 3 AP
Benefit: Grants you 10 additional hit points if you have the Toughness feat, bringing the total increase to 30 hit points.

Maybe a fourth one, but three seems good (it's still less than Barbarians, Fighters, etc. get, and with higher level/point-spent/prerequisite requirements).

Ideas for refinement? Pros? Cons?