I have just bought an airbrush based on
@James Duffy's recommendation. I also have a decent stock of Krylon Acryli-Quik paint, but am not loving the limited color selection and extremely limited availability with high shipping costs. Createx and Tamiya are available at Hobby Lobby and elsewhere locally. Are they compatible with the Acryli-Quik? Can I gradually move over to airbrush and mix it with the spray can stuff, or do I have to go one or the other on a given rocket?
You should have no problem spraying any acrylic over a fully cured base coat of spray paint, either enamel or lacquer. I do this all of the time, and it is in fact the approach I use 90%+ of the time.
Spraying acrylics over fully cured layers of different acrylic brands shouldn't present a problem, either, although I cannot say this with 100% certainty. Testing first on scrap material is recommended.
Mixing different brands of acrylic paints wet will probably
not end well, though. If you need to create custom colors it is best to stay within a single paint line from a well-respected brand. (I'm a big fan of the Tamiya acrylics.)
Another tip is to use only the thinners designed specifically for a particular paint line. If you're spraying Tamiya acrylics, for instance, use the Tamiya acrylic thinner. (Can you tell I like the Tamiya products?)