Ok heres how i look at it:
Manny(1) & Prior(2) : This is alright, manny is a beast, who knows about prior and whether he will dominate or not. this is your second best option.
Santana(1) & Teixeira(2): Santanas nasty, but why teixeira in rd 2, u sure there wouldnt be a better option.
Big Unit(1) & Sheffield(2: As a sox fans this hurts to say, but this combo is nasty. I had a variation of this last year and it worked out nicely(scheff, schill). But the injury risk is x2 with these guys. Plus their yankees... and honesty, it would suck to have your two best guys be yankees. So hard to root for...