I go to a local auto-parts shop, they usually have cans from different makers, at mush less cost than others. I also use Graff paints. Used the Montana brand - gold for minis and models. Spray outside or with extraction always.
I found Molotow - Beltone to be the best. Good colours, good coverage, not thick. Due to the Graff type nozzles the paint goes where you want it, not too broad a spray. They are really good for use in all weathers, damp, hot, cold. The Matt is really good, low sheen at 1st, but after a week or so it goes nicely flat.
I find car primers are the most temp sensitive and can blume in some weather conditions.
I find all 'matt' clears have a sheen when coated on to stuff Ive used ink washes on. So often a light spray 1st with full coat a week or so later.
The Graff paints just have a good set of colours, as said not all very matt, but if your top coat is matt does that matter.
Oh and yep some are very smelly, especially the yellow mixes.