Do you have the kit now? They usually come with some included coils. My recommendation would be to try some of the ones that come with the kit to figure out if there are some you like, and or some you hate, etc.
Resistance IN GENERAL but not 100% guides wattage, and in general the lower resistance of the coil, the more wattage it may require to make it vape satisfactorily.
I would seriously try using some of the coils that come with to get a general sense of the tank, and what sort of resistance you enjoy.
If you like hate them all (you .probably won't but people do) smok tanks take some non proprietary coils from other manufacturers but unless you are trying to make sure you have enough, well just buy some of them a few of them, enough to keep you going until you figure out what you like and etc.
It's just a suggestion but many folks do find they prefer a particular coil and/or wattage/resistance range.
Anna