No love for Cliff Floyd? He's easily the best player on that list. If he stays healthy all year he could easily do .300-30-100-100. If not, its no big deal because he's on your bench.
I really don't know what people see in Gibbons that would rank him over Floyd. He hit for a better average last year, but at the expense of a lot of power. He's also got a checkered injury history just like Floyd.
Patterson is a bit of a question mark this year - it can take 2 years to fully recover from an ACL injury. He's got Beltranesque upside though, so I would keep him.
Burnitz is intriguing, but his BA is going to hurt you regardless of how many homers he hits.
So to sum up, I'd keep Floyd and Patterson.