Okafor at an average of $13 million per, no thanks. To me Okafor is a slower, stronger, smarter, less athletic version of Sam. He is a terrible FT shooter and although a good rebounder, he ain't exactly Kevin Love on the outlet pass. His offense is very limited and I don't see him improving much. If I had my druthers from the big man RFA pool I would get me some Biedrins way before Okafor. Biedrins is more mobile and produces at about the same rate as Sam and Okafor, but is considerably younger and more efficient. He also seems to have the best basketball sense of the three. Biedrins is also a poor FT shooter, although not as bad as Okafor.
With Brand, Speights and Thad possibly inhabiting the low block for the next several years, an ideal replacement for Sam would be more of a high-post center like Bogut, although not at the salary he will be making.