Let me clarify on the changing of flavors. I'm not looking to change throughout the day. More along the lines of trying a new flavor every now and again. Order a 5ml bottle of something and fill up the tank. If I don't like it rinse it out and change the cotton is all it take unless I'm missing something. A lot better than trashing a carto while not expensive aren't cheap to just be tossing left and right either.
I definitely want something with a tank on it, not a dripper. Seems the Kayfun is popular choice at the moment, anything else I should look at? What particular one should I be looking at? (seems to be a ton of variations out there)
Well it still boils down to confusion as to whether it is a rebuildable that you want or not.
If you just want to change flavors without having to clean a carto, a common tank is all you need; just either replace the head and put the old head to soak, or just change the liquid and don't bother with the small amount left over taste which you'll only notice for the start; a carto holds alot more liquid in the big wad off filler material compared to the common atomizer heads which have only a small wick, especially the bottom coil heads.
If you want to wire you own coils and put your own wick then rebuildables are the way to go, but for changing out flavors, many rebuildables are not as convenient for changing out the liquid inside the tank as many of the common tanks.
My I-atty genesis type rebuildable I have to use a syringe to put liquid, or remove from the tank; many rebuildables have a 'fill hole' like it where you basically need a syringe or if there's enough space a needle bottle might work - not mine, too small for the needle bottle to work. In fact that's one of the main reasons I stopped using it.
In comparison, with the protanks, I just unscrew the base, which has the atomizer head on it, and take the tank to the sink and give it a rinse then shake out and fill her up.