With sugar free alternatives is bit of an problem with taste - steviol is bitter for example. It usually needs to have some combination of 2 or more artificial sweeteners and they can affect the taste. So you will probably need more experimentation with the recipe.

I can get most of the essential oils from local supplier that sells it even to normal people and you don’t need a business. I think they can ship EU wide and the smallest quantity is 30ml. https://fichema.cz/