Now for a counterpoint. I have actually used the Paint Shop paints, and it does work very well. Prep is key, the better the base primer under it is, the better the finish will be. That goes for any finish, regardless of whose brand it is. You could use the $300 a gallon paint and still get a poor finish out of it. With the right prep, you can get a good finish out of the $25 a quart paint.
The Paint Shop is premixed, ready to spray lacquer. No hardener needed, though I think they do have one if you want a tougher finish. It is base coat/clear coat. Lays down very well, takes to the Norbie Technique very well.
Unless you get a fantastic deal on a used gun, a Harbor Freight gun will spray it just fine. I've been using one for a while now, it actually does a better job that the high dollar DeVelbiss I used to use. I have no problem suggesting them to a novice/hobbyist who does not have the need or budget to spend the money on high dollar equipment.
I used this paint on the bumpers of my truck, turned out fine and is showing no deterioration since I painted them about 4 years ago.
