I don't see Kotchman full-time at 1B. Not enough power to offset the power reduction in the OF.
Beltre looks like the best option, provided they can sign him for $10 mil or less. He'll give them Lowell's HRs (last year doesn't count because of injuries), and VMart/Cameron offset Bay. He also fits their defensive plan, and that includes keeping their pitching advantage by not trading Buchholz.
The other option, AdGon, gives them more HRs than last year, but they give up runs on pitching and defense (Youks
Beltre looks like their target to me, but they may have to deceive a bit and get Boras down from his sky-high price.