Here's a link to the buying guide I used. I haven't got a chance to try them out yet but it seems to have worked for several people I've seen reference it:It'd be interested to know the size rods bought to cover what calibers?
Also procedure for checking straightness and how to straighten.
My specific process is probably going to be out of reach for most.
I work in a Tool and Die shop so I indicated them between v-blocks. Then I just rolled them to the high side and pushed down on the high spots until they straightened out. It's pretty basic and once you get the feel for it, it goes pretty quick.
I also had time to kill so I chamfered the ends and laser engraved the size and calibers on them lol