Take a look at Hampton's 2nd half numbers from last season. He was quite impressive, and I think he'll have a solid year.
I dont like Garland much, and but Carpenter I'm not sure about. He has pitched very well this spring and I suppose you might want to take him over Lieber. However, both have injury concerns. On the other hand, Lieber plays for the power packed Yankees. So, I'm not sure. These guys don't have a big enough push in my mind to validate dropping Lieber for one of them.
Prior would be a good pickup. I think Santana will have a very good season, but if you can get Prior, you pull the trigger.
I too, think Millwood is a tad bit overrated. However, he's still good. Keep in mind that there was scuttlebut going around of Affeldt possibly closing out games this season.