It depends on what you are looking to spray out of it (type of paint)
Basecoat and clearcoat are not the same to spray (especially a basecoat with a lot of metallic in it)
Basecoat needs good atomization for the flake to lay decent without getting tiger stripes & mottling.
I usually have a gun to do base, 1 to do clear & 1 or 2 for different types of primer.
(everything has a different viscosity & that's why all guns are not the same)
If you are doing single-stage color, the primer gun would probably work for that also.
I like Sata guns. DeVilbiss has always been good. Some like Binks (I don't) Some guys claim they can lay out a good paintjob with a harbor freight cheapie. A lot of it will depend on if you are painting stock cars, or trying to do a show-worthy job.
Go to an automotive paint place ( somewhere that specializes Only in auto-paint) & tell them what you want to do with it. I used an Accuspray years ago that claimed to be able to spray anything. It had different air-caps & different tips that all worked in the same gun body & it worked ok. It wasn't cheap, but it would be cheaper than buying several different guns for different applications.