I have played in 1 league like that and I would pick up as many QBs as possible. You have a 12 team league so only half the teams would have a backup. Its not like having a RB by committee where you get some points a week. Either they start or they don't. When you get six weeks into the season there are QBs that go down and their backups are horrible and then others that have bye weeks. This makes for some serious tradebait. You can get a real good #2 RB or maybe even a top 15 RB for the likes of Plummer, Garcia, or maybe even someone in desperate need Brunell or Harrington. I would get a 2 RB and then seriously start going after QBs. You will be amazed at how quickly someone is willing to trade when they are starting Banks and Feeley.