Fitzgerald is a no-brainer here. He is a stud, and Kolb is looking his way a lot the last couple of weeks, as he well should.
I would take a chance on Amendola against the Cardinals considering what Brian Hartline did to them last week.
The third WR is a bit trickier. It looks like Jennings is going to find himself on the injury report, and rumor is he won't play for a while, so you can probably rule him out. Maclin only had one catch last week, although I do think he has talent, you just cannot start him. Moore I'm not too sure about either.
I would hesitate to start two Cardinals until their passing offense picks up, as you hint, but it looks like Roberts is your best option here. Roberts is coming off a monster week, and we have seen this before in Arizona where a #2 WR is the beneficiary of Fitz getting double coverage all the time. Kolb is not a great QB by any stretch, but I think it is safe to assume Roberts will continue to get looks as teams focus on Fitz.
QB: R Griffin III, A Luck
RB: A Foster, F Gore, T Richardson, K Hunter, M Hardesty, A Green
WR: V Cruz, M Austin, P Garcon, S Moss, B Hartline
TE: J Witten
K: Matt Bryant