I don't like the idea of trading Jamison, and I don't think it's a realistic option. He signed with the Lakers for less because he wants to win a championship. Plus, he doesn't have much value to anyone. He's too old to trade for prospects, and no real contender would want him.
I do think that our PF rotation would be good enough with Pau, Metta, and Jamison. Hill is valuable and rather expendable.
It would solve a lot of our problems if we could trade Hill for Dorrell Wright. He's a good shooter from range, despite his low FG% the past two seasons, his 3FG% has stayed pretty high and I'm sure his FG% overall would improve playing with Nash.
Wright is also a very active defender and athletic, so he would help in our transition defense.