Should Pistons get one of those player below?

Chris Kaman/Elton Brand from Clippers, JO from Pacers, Yao Ming from Rockets, Emeka Okafor from Bobcats. If so, how are they gonna do it. I don't think they will trade Sheed, because he's pretty good, his post up is nearly unstopable (similar to Dirk's post up), I think the only thing is they need a true center, see when Big Ben was here, we were pretty good. Since he left, we have a lot of problem inside. So I think the only piece that we have fill is a center, not a PF(sheed) tried to be a center.