How is this impacted for those siphon brushes that have the metal cup hanging off the side? Do those also come with multiple cups, or is that kind of a grey area?

I am in one of those positions where I actually have some cash to spend that has to be spent on fun stuff, and I am really leaning towards spending some of it on an airbrush. I want to make sure that I get something that will be useful for me for a while so I don't "waste" my money. So I really appreciate the help with all these questions!