To help the quality of upcoming posts in this thread, here's a link to a list of FA O-lineman:
2010 NFL Free Agents: OL
As far as starters go, I can honestly see Derrick Dockery being the only incumbent. Samuels should retire, I doubt Randy will be back, Rabach and Heyer are bums, and I'd be surprised if Edwin Williams or Chad Rinehart could earn a starting job.
I think we need to build the entire O-line around Armstrong.