These seem like great buy low opportunities.
This isn't about bargain hunting, this is about bringing in a proven arm to supplement and help guide those on hand.
To me, Capuano is the best fit. Numbers-wise, he isn't the best of the group, but he's more of a ground ball pitcher - which fits into a lot of the O's pitching philosophy.
If you go by the numbers, Harang would probably be the best, but his SO rate has gone way down since his best days in Cincy.