Much of the old acrylic is no more I am told and it’s more urethane enamel now but still single stage. Regardless, I just shot my first vehicle with the cheap HF $18 paint gun and paint from TCP global. It’s just paint and hardener, easy to, easy to spray (plenty of you tubes out there talking about the cheap HF gun and how to use it), and although it’s cheap, nearly does the same job as the expensive guns. Also, consider buying the gun stand - its easier to load the gun with paint with it vs without. TCP Global has a wide array of colors, many if not most all the old colors as well as new ones. I am just finishing a 40 pickup and I would say you would need 2 Gallons to be safe. I used flattener in a 1:1 ratio with the paint and I am using up just short of a gallon. This paint does not take any reducer so it’s really all paint, hence the two gallons.
I used an air regulator at the gun along with a little golf ball like water filter to keep out any moisture just before the regulator. Just remember I have added flattener hence the non-shiny finish. Some pics ....