Kickers and defense are so luck based that i dont feel like wasting my time trying to get the "best possible one". Remember Greg The Leg? He was all the rage four or five weeks ago and hasn't done jack **** since.
One manager in my league picked up Connor Barth last week because Oakland has given up the most FP to kickers this year. He lost by one point and if he had played his regular kicker, he would have won.
It's anecdotal evidence, but kicker's and defense's are pretty much fire and forget. Unless you know that a defense is going to face some blind kid from the make a wish foundation or some kicker can hit from 90+ yards out, there just isnt any point to putting any more than the minimal effort.