You should never have two K, EVER!!
But out of those 3, its Vinatieri for me. Great Kicker, Great Offense, and I dont see whats wrong with Indy's schedule?
Not like the other two are bad options; but hartley has been so garbage so lets ignore him. And SD does not kick many fgs; Kaeding has attempted 3 or more fgs just once, while Vinatieri has done it 4 times!
Just monitor the weather too, Indy & SD have some road games in playoff weeks, so if weather is bad, all of the above becomes useless.