Mech mods work best with low resistance coils, since you are relying on the charge of the battery minus the voltage drop of the mod/atty to determine what voltage your coils are getting. IMO, for a Nautilus or any
tank system that uses prebuilt coils, you'll get a better Vape experience using a regulated device like an Istick or a dna box mod.
For the magneto, I'd stick with rebuildables since your build controls how you want your resistance to be.