I'd go with Fitzpatrick over Kitna. Indy actually has a very tough D against the pass, and are at home in a must win. Fitz has 19 TD passes in his past 9 games, good for 3rd in the NFL over that span (behind only Cassel and Brees). Also, Minnesota has allowed 8 TD passes in their last 3 games. Kitna is good, but Fitz has a chance to be top 5.
I don't like the matchups for Welker or Wallace, but they're both great players. I'd take Wallace, because in spite of one bad week, he has been the far more explosive of the two, and had been much more consistent to boot.