Human Paragon gets to select his class skills, 1 stays a class skill in whatever classes you take afterwards(gets even better if you slap on Able Learner).
I'd recommend taking all 3 levels: 3/4 BaB and 2/3 casting, 1 free Feat & a +2 boost to an ability you choose.
Not sure, what you want Binder for, considering your soulbinding level will max out somewhere between 4 and 5.
If you cast on WIS, Incarnum is never a bad choice and scales partly with character level.
With Practiced Manifester you might get some use out of Psionics(Ardent or PsyWar, comes down to Bonus Feat vs. Mantle Powers).