I think we need one FA lineman, just because we can't realistically ask next year's line to be four rookies. I'd love to see Tomlinson as our starting guard (he fucking abused Aaron Donald three weeks ago, watch the film) and I'd love to have Tyrell Crosby come in as a backup at both tackle spots and possibly push for a starting RT spot. He's not great but he doesn't hurt you either; exactly what you'd want in a backup.
I'd love Linderbaum and Ekwonu as well.
Just imagine, next year's starting line could be:
Thomas - Bredeson - Linderbaum - Tomlinson - Ekwonu
You could have Crosby as your tackle backup, then hope you get something out of either Gates, Limeaux, or Peart in a backup role at guard (honestly though, i think all three of their careers may be over).
We'd go from league's worst line to a B- line, with the capacity to develop into an A+ line in the next two years or so.