I fully expect to see Manning sign with Miami. I realize Denver was his first visit, but I don't buy for a second that Peyton will choose to play in a cold weather venue. I think it comes down to Arizona and Miami. Miami's got more going in it's favor IMO because they are a warm weather AFC team, he likes the city (already has a home there), they can offer the best LT in the NFL to protect his blindside, have weapons such as Brandon Marshall and Reggie Bush, and it sounds like Miami wouldn't be opposed to bringing in FA's Reggie Wayne and/or Dallas Clark to help Peyton's transition be as smooth as possible.
Peyton is in the middle of doing his due dilligence because that's the type of guy he is, but in the end it will be the Phins.