Oh yeah you can get the paint easily online. Tamiya and Vallejo are on Amazon, Vallejo has some nice variety packs where you can get for instance all their metallics, which gives you your aluminum, steel, rust, etc. The model air is prethinned for airbrushing but you can brush paint with it also, you're better off brushing paint that's kinda thin because you won't get as many brushstrokes.
You might get lower prices at a hobby shop though, mine sells the Tamiya jars for around $4.50 each, the Tamiya jars on Amazon are a little over $7 each.
Vallejo makes a black metallic in their model air that is pretty good for this. Might give you the look you are after. I ordered some on Amazon a while back, but I’m only finding a metallic paint set that contains it now.
Vallejo Metallic Set Model Air Paint, 17ml, 16-Pack https://www.amazon.com/dp/B001G6NH1G/ref=cm_sw_r_cp_api_i_ZPf1EbHZYJEZ1
I was considering this one from amazon https://www.amazon.com/dp/B001G6NH1G/_encoding=UTF8?coliid=I2AZAYCMBXP75S&colid=3QU0XRVIP3PBQ
I understand they are "finer" for air brushes, but a lot of people keep raving about them. Air they just better for metal even when compared to the non-air metallics?
They are in nice screw top dropper bottles. Cost depends where you are I guess, in the UK they are ~£2 for a 17ml bottle if you're buying individually or you can get sets like this which is what I did.
My plasure, should have read your post more closely where you specifically said Airbrushing, my bad.
Vallejo acryllics has a metal line that is better than the standard Vallejo Model air silver and comes in an aircraft aluminum. Still not as good as some of the other options but overall better than the base Ma silver and it has absolutely no bad smell or fumes which is a big plus for me since I have no method of ventilation yet. I really should have mentioned that in the previous post but it slipped my mind until I knocked the box for it over.
(Still wear a dust mask as it does put some particles in the air you'd not want to breath if you can.)
I finally made a choice and went with the game color set.
I have however added the metallic set to my wishlist. Maybe I can justify it to myself by christmas :)
vallejo model paint air Metallics
https://www.amazon.com/Vallejo-Metallic-Model-Paint-16-Pack/dp/B001G6NH1G