Barbarian Dilettante enhancement stacking

[Carpone]

With regards to a Half-Elf 12 Fighter/8 Monk with the Dilettante: Barbarian feat...

Can Half-Elf Barbarian Constitution I and Human Adaptability: Constitution both be purchased? Or does purchasing one of these lock out the other?

Can Half-Elf Barbarian Toughness I and II be purchased along with Fighter Toughness I and II? Or does purchasing one line lock out the other?

[Truga]

With regards to a Half-Elf 12 Fighter/8 Monk with the Dilettante: Barbarian feat...

Can Half-Elf Barbarian Constitution I and Human Adaptability: Constitution both be purchased? Or does purchasing one of these lock out the other?

Can Half-Elf Barbarian Toughness I and II be purchased along with Fighter Toughness I and II? Or does purchasing one line lock out the other?

Constitution enhancements _should_ stack (class and race usually do), but don't take my word for it, because I don't have a helf and thus have no idea how dilettante works.

Toughness enhancements will lock eachother out, since they are both class enhancements and do the same thing.

[unbongwah]

Can Half-Elf Barbarian Constitution I and Human Adaptability: Constitution both be purchased?

Yes.

Can Half-Elf Barbarian Toughness I and II be purchased along with Fighter Toughness I and II?

No.