I still don't see a reason to re-sign Davis. He's a known quantity--above average at everything and recovering from a serious injury. If he signs for cheap, or signs a "prove-it" contract, then fine. But his skill-set isn't special and we were a top-5 offense without him. I'd like a player who can make a larger impact and have a more defined role on this offense, personally.
Jared Cook is a good option, and hasn't reached his potential on a bad Titans team...he's exactly the kind of guy you sign in FA for less than he's worth going into his prime.
I'd drop Davis for Cook in a second. He brings another element to this offense that Davis just can't, and you avoid the injury questions with Davis this way as well. We let our own FA's go for other teams' stars for so long, with negative consequences, that Skins fans seem to actually think its NEVER a good idea now.