I agree with Masher.
The order of the pitchers is definitely (1) Unit, (2) Schilling, (3) Pedro.
Take Soriano ahead of Schilling or Pedro, IF you believe Soriano will not have a significant decline in production from last year. There's no particular reason to think he would, other than his high strikeout / low walk rate, but that is enough to make some nervous. If you feel comfortable that he'll be a 40/40 guy again, then go with him.
In any event, you can hardly go wrong with any of 'em.