I'm with Phil. Tamiya is a solvent based acrylic - which arguably really makes it a lacquer. (I strongly recommend using either Tamiya or Gunze lacquer thinner with Tamiya paints - Tamiya A-20 acrylic thinner is glorified ISP and does not lay down as smooth a coat. Many people have used A20 for years and tend to be very good with an airbrush, and perhaps it doesn't matter for them. But lacquer thinner is the way to go. I think the solvent based lacquers call themselves "acrylic" to show that they aren't enamels and are very different breeds than hard core Alclad style lacquers which have very strong odor and require something like a gas mask.) Tamiya is flammable and toxic - that's enough for the lacquer classification. It is, however far milder in odor than lacquer model paints like Alclad. It also uses dyes for the pigment. This means bits of natural pigment won't clog the tip. It also means that the solvent agent is akin to the thinner, so if you thin Tamiya very heavily, it will keep it's chemical integrity. So you can thin Tamiya 20-80 pretty easily with very good results: tough with other brands. Compared to an enamel the odor is far less and like all acrylics it dries much faster. Indeed, you will want to keep a damp paintbrush nearby to occasionally wipe off the tip of the needle if the spray starts to slow down. Gunze is similar paint. Tamiya paints mix perfectly well with each other, so if you have a jar of the primes, along with white and black you can expand the number of colors at hand hugely if you like to mess around a little. (I won't swear something bad would happen, but I wouldn't mix Tamiya with Vallejo.)
Vallejo, LifeColor, Revell AcquaColor and art brands like Golden are have an agent of water solable polymer mostly. Vallejo comes in two brands: Model Air and Model Color. Model Air is made to be airbrushed almost neat out of the bottle. (I do like the teardrop bottle much more than the Tamiya jar.) It can be thinned with water or Vallejo thinner. Vallejo's chemists don't write me often, but I'd guess it's mostly water along with some conditioners, flow levelers and drying retardants. It's worth the money. You shouldn't need much thinner, but there can be trouble if you want a heavily thinned paint for some kind of detail. (It doesn't matter if you're using heavily thinned paints for filters or washes - the integrity of the coat is irrelevent there.) LifeColor and AquaColor are thicker than Model Air, but I'd guess Vallejo thinner - perhaps along with some flow aid drying retarder - would work pretty well. Model Color is thicker and is made more for hand brushing. You can easily airbrush with it if you get some "Airbrush Medium" from art brands like Golden or Liquatex - Vallejo also makes it. It should be very thin but white. The medium is a heavily thinned polymer so if you thin the paint heavily - you'd probably need at least 30% thinner - maybe 50% - the integrity of the paint is extended and the chemical structure will remain sound. If you thinned Model Color with just water, it would work badly. (Golden's website has a lot of information on why paints act the way they do. Interesting stuff, but hardly necessary.) Vallejo has an endless array of colors and are very good paints once you get used to them. They are non-toxic and non-flammable. You should still wear a mask because you really don't want pigments in your lungs - although I forget a lot. No odor at all. Easily cleaned when wet. Vallejo will dry extremely hard over time - never use it and forget to clean the airbrush.
Vallejo is great paint. I like Golden High Flow even better: the only water based acrylic that can be easily sprayed neat with excellent coverage. But you'll have go to an art store for that, whereas Vallejo is available anywhere. But if you watch a lot of build videos done by fine modelers, I think you'll find more Tamiya used than any other brand. Very common for someone to use Tamiya for most things but Vallejo for hand brushing or perhaps for a primer. No difference in price in the real world. (Actually maybe that's bad. I buy Vallejo for $2.50 a bottle - heavens, that's less than $3 - less than a Big Mac - let's buy it. Multiply that logic by 200 times and .... well, all economies require consumption to function.)
Do remember that if you used acrylic products over an enamel base for panel lines or weathering, but you'd normally reverse the order here. That said, if you keep an acrylic base coated with some kind of varnish or pledge, you can use acrylics for all kinds of weathering. Not recommended unless one really dislikes enamels or oils for that. That said, Vallejo is really pushing "all acrylic" modeling at present. Check their 50 min long YouTube video "Acrylic Weathering Techniques" or a recently published book of the same title is 200 pages of information and photos on about everything.
Eric