I checked this out when I lived in Mexico and couldn't find any source for CAP, TFA, FW, etc. McCormick for example, most of their flavorings are extracts. In other words, they're oil based. Don't vape oil.
Also, most supermarket flavorings contain artificial colors. Even McCormick's Imitation Vanilla contains caramel color, among other things. Those aren't necessary or desirable for our use. I'd avoid the potential risk of inhaling them.
Then there's added sugars. McCormick has a flavor called "Premium Vanilla" I bought it because of the vanilla ice cream picture on the box, just to see how it would compare against other VBICs. Should have checked the ingredients first. Corn Syrup.
There are a few exceptions. Their Hazelnut would theoretically work, but my experience with it is it's very weak. I tried it, impractical ratios, like 30%, were necessary to get anything out of it, and it was very heavy on the alcohol.
If you're looking to locally source flavors that work (assuming you're in the USA), Michael's Art Supply carries LorAnn, but unfortunately they seem to favor stocking the colored versions. I don't have any data proving colorants are dangerous to vape, but it's just an element I'd avoid since it's not necessary.