It would be a tough choice between Michael Huff and A.J. Hawk; I think I would go with Huff in the end. Singleton may not have won us any games but he didn't lose any for us either. Davis DID lose a couple for us and we really need that FS spot filled with a true talent.
My other considerations:
I have Haloti Ngata (sp?) down as a strong #3 guy but several paces back because we have Jason Ferguson who is ageing but still there and "Pepper" Johnson can rotate with him and be servicable
Not my #4 D'Brick Ferguson because we will be getting Flo back healthy and signed Fabini. If Flo gets it going again he could be one of the best and Fabini is servicable until Pettiti grows up into the tackle he WILL become.
Not my #5 Mario Williams because we have Canty, Spears and Ellis. Two young studs and a vet who can play eoither end...plus a couple of servicable young backups for rotation.
As for Bush; He would be great but I have always considered a top shelf RB to be a last piece of the puzzle. Once you have everything else in place then you get your stud RB. That way he is not getting the crap beat out of him and leave his best work on a losing field while you build a team around him. And I have not yet written off Julius Jones though he better do something good this year and not get hurt.