I'd put Peyton Manning ahead of Brady given that he is playing for a new team that didn't know how to play with a throwing quarterback last year, leads the league in passer rating, has already engineered at least 3 4th quarter comebacks and winning drives this year. Tom Brady, on the other hand has an affinity for all his skill players from having played with them.
As for receivers, if you are going to mention Welker, why not mention Wayne. For the same reason as listed above (affinity with the players and the program), Wayne is essentially playing a new position in a new system with a new quarterback and new receivers and he's second in catches and first in yards. What he is doing for the colts this year is amazing.