I'm in a similar situation albeit in an AL only league.
For some reason even though he's ranked lower (yahoo) I like Callaspo over any of the other AL 3bs but again that's AL only. Here's how I'd rank the 3b you listed.
Mcgehee: Looks like he's assured of a starting spot, perfect age and playing for a potent lineup. Callaspo: Okay, probably irrational because he may not even be starting in three weeks but I like his numbers last year and he's been super hot this spring. No, I'm not a Royals fan. Inge: and if he gets hot out of the gate I'll probably grab him since he's a streaky hitter and he's healthy this year (he's been hot this spring so keep an eye on him). Rolen: injury prone and power dipping but could surprise if he stays healthy. Peralta: I also considered Peralta but was put off by his dip in average and power. Teahen: Some potential and maybe the change of scenery helps but I'd look elsewhere. Headley: great potential. A year away if he played anywhere but Petco Lowell's just not going to get the ABs that other full-timers will get though if someone gets hurt for the Red Sox he moves up the list considerably.
Keep an eye on Garret Atkins if he's available he could be done or maybe they'll fix his swing in Baltimore and he rediscovers his power.