Settings are a whole different world of possibilities. But if you have a mod with a common tank, there are shitloads of coils you can find for it, because some things are standardized between many makers. I can literally buy at least hundreds of different sub-ohm coils from dozens of different makers, and you also have some stores making their own and selling for cheaper.
For instance, some of the coils will claim they are 0.3, but they are really 0.26, some are meant to be 0.5, but they are really 0.48 etc. For proper output calculation, the mod has to detect the real resistance, and you can also see it on its display:
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Then the lower you go, the more granular the coil makers get, so you can buy 0.1, 0.12, 0.15 coils etc.
eGo only accepts coils made by Joyetech, and they only make a few for it. Possibly the eGo coils work the way you described, as I remember different resistance coils there being also built differently and offering different air flow levels. But generally speaking (all things being equal) the lower the resistance, the more smoke you get and somewhat less intense flavor, at least relative to the cloud you get. The coil also reaches higher temperatures faster, potentially burning the liquid's flavors more.