Who to Start as WR2?

So I have a team that is pretty deep at WR, and I'm uncertain who should be starting at Number 2. I have Jennings and Ryan Matthews as my flex vs. KC starting for sure, so I can only start one of these:

Santonio Holmes (vs. OAK)
Mike Williams (TB, vs. ATL)
Santana Moss (vs. DAL)

This team is pretty good, probably my favorite team that I drafted. I believe I had the Number 2 Pick.

QB: Tony Romo
RB: Adrian Peterson
RB: Matt Forte
RB/WR: Ryan Matthews
WR: Greg Jennings
WR: Santonio Holmes
TE: Fred Davis
DEF: Bears
K: Ryan Longwell
BE: Mike Williams (TB)
BE: Santana Moss
BE: Marshawn Lynch
BE: Chad Ochocinco
BE: Willis McGahee
BE: Ryan Fitzpatrick
BE: Dexter McCluster

Although, admittedly, I'm screwed if Peterson or Forte goes down.

Also, on a different team, is Dwayne Bowe or Frank Gore worth sitting for Hakeem Nicks, who is playing against Philly and has injury concerns?