I direct you to : https://www.prowin-tools.com/applica...vlp-spray-gun/
note the air volume difference. But with a mini gun it would be less of an issue. Just like the price of full size guns, price of mini guns can also vary dramatically from $20 to over $500. I mostly use star mini guns, which are probably at the lower end of mid range. Not all the bells and whistles, but it works for me. As for the nozzle size a lot depends on what you are spraying. 0.8mm would need more thinning for what I spray than the 1mm I use mostly. I have a 0.8mm, also a 0.5mm (you are hitting air brush territory there). Admittedly you don't need to be as extreme as me, I use 3 x 1mm mini guns, a cheap and nasty one for primers, and separate ones for base coat and clear coat. With good house keeping one will do.