Don't put a rookie Q out there at all. That's been one of the problems with this team. I'm not going to argue the qualities of Losman and Edwards, but I will say that putting a true rook at Q usually doesn't work well.
YES, there are exceptions. Please (not necessarily you, Dr.D.) don't come back with Brady this or Manning that. A good QB sits for two years and develops, most of the time.
There are more Rodgerses (yeah, that's the correct plural despite the B-Lo tendency to add an apostrophe when not needed), Kellys (don't think for a second that the USFL didn't help him develop, and don't forget his record in '86), and Breeses (see Rodgers on the plural) than there are Mannings or Bradys. A good Q needs time, a good line, and a good coach. I think the BIlls have a decent, but not great, line; I also think that Gailey, while not a SB coach, might be the guy to develop a young Q.