I load rifle ammo 223, 22-250,243, 308,0-06 on a dillion 650. 223,243,308 were across the coarse high power ammo. I also load 380, 38spl, 357, 40 s&w, 10mm, 44 sol, 44 mag on a second 650. 357 herret, wild cats get loaded on a single stage. I load 45-70, 45-90, 40-65, 38-55 on the single stage as they are black powder ammo and loaded in lower quantities. But the 650 would do them fine.
I have all my dies in tool heads and the only thing to add is the measure. the lower end isnt bad to change over.
In Dillons publication The Blue Press is a section listing all the presses their capabilities and information. Be honest estimate the ammo needed quantities and uses then look in this section and see what meets your needs.
Case preps is easier to do outside the press before hand. uniforming pockets, deburring flash holes, trimming, I your loading military pick up the dillion crimp remover when you buy your press. Another to remember is these machines are lot faster so case cleaning may need to be upgraded also. These machines work best on a solid bench also.