Dunn's career: .245/.380/.513; OPS: .893
2006 MLB average LF: .276/.348/.456 OPS: .804
2006 MLB average RF: .277/.345/.458 OPS: .803
2006 MLB average DH: .261/.356/.485 OPS: .841
(I realize these would be a little unkind to Deer's early career-but they make the point)
While Deer was actually an above average defender, I'd go with the one that was a plus bat at his position. Above average defenders who can't hit are pretty easy to find but they aren't very useful DHs. There are ways to maximize Dunn's production while minimizing his weaknesses... Deer, well, not so much.
But that's just me...