The deluxe kit is not available from the supplier (BearAir) I am buying from, so what else besides the AB do I need?<<
That depends on 1) Do you have money to burn on luxuries which would really help you, or do you prefer to do things by hands, but save on money? And 2) what paints are you going to spray?
I see references to metal cups and extra jars–are they necessary, and why?? It comes with the medium nozzle/needle.<<
You wouldn’t be able to make very thin lines with that. On the other hand, I’m unable to make thin lines even with fine nozzle/needle. Anyway, there is no real need for overly thin lines.
Extra jars are needed for mixing colors. If you would buy pre-mixed colors and don’t mix them yourself, you don’t really need them all that much. On the other hand, I wasn’t able to paint without mixing colors. You will need one or two jars with cleaning solution in them, for fast-cleaning your airbrush between colors (I use simply water with a bit of detergent for that.)
All in all, jars are useful. On the other hand, they cost an arm and a leg. On a gripping hand, I’ve found that small hermetically-closing bottles in “medical and laboratory equipment” shop are far superior to any expensive jars (with exception that they can’t be directly connected to the airbrush, but I never use standard jars for painting either, I always use metal cup), and cost $4 for 20 bottles. After purchasing them, I only ever use one big jar for cleaning solution.
Metal cups are good thing - I always use them for spraying. Well, since I have only one of them, I have to clean it between every spraying, which takes like 10 minutes and a bit boring. Thus, I would advise to have 2 such small cups, or 3 if you have money to burn on luxuries.
By the way, when I need to spray just a tiny detail, I turn my airbrush upside down, and drop just a couple of drops into connector, without any cups, thus turning it into a gravity-feed airbrush, and use it upside-down. If you need to spray mostly small details and areas, think about gravity-feed airbrush - it uses a bit less paint. For average and large survaces there is no difference.
An interesting luxury is ultrasonic cleaner. You can, of course, clean your airbrush by hand every time, but you can buy a relatively good ultrasonic for $25 (don’t forget to check specifications - you need one which have at least 35.000-40.000hz (or, in other words, 40khz), there are some models with, like, 100hz cleaning frequency sold as “ultrasonic” - they are not, they are “sonic”
) It’s a pure luxury, but the one which really makes your life easier.
Oh, and if you spray acrylics, needle lube is a must. It’s a pain in the a$$ to manualy remove paing from needle’s tip every 20 seconds. It can be done, I’m doing it right now, because I’m cheap and don’t have it, but I’d rather not.