An excellent resource that my help you can be found
here,
Unfortunately it is out of print and the cost right now is really high. One interesting part of the book compares the "premium" dies with just routine dies. There was no clear cut winner. So just because you spend the extra money for say a premium bullet seating die, your loaded ammo will not have less bullet run-out. The data was interesting.
My reason for asking the questions I did, was to understand what "quality" of ammo you are currently producing. If your bullet runout is 0.006 to 0.008" TIR, the technique you use to set up your die can impact the results. Using an O-ring under the die lock nut allows the die to center itself in the press. Tightening the bullet seating lock nut on the stem while under compression from seating a bullet will improve (reduce) bullet runout. Just some things to consider.
I have Redding competition seating dies but I can adjust a standard die to seat just as accurately on OAL.