I understand the "ohm control" question.
Some mods provide this possibility (change the ohm value of your coil) mainly for temperature control accuracy.
Some old joyetech/eleaf/wismec mods, once tweaked with Arcticfox firmware, give that possibility.
Old pico 75, pico 25, Ravage, Espion, Rx75 for example.
Only models with a classic micro usb connector.
The hardest part will be to find one, and tweak it with Arcticfox.
As Arcticfox is now a closed projet, you'll have to find somebody to send you the correct files for your mod and teach you how to install it.
I can give some help if needed.
I now some other mods can do that natively but i can't remember the ones ...