Hi Joe,
Being a professional auto spray painter, i can offer a wealth of advice on this topic. As i recall, i am sure i have posted in the past a good amount of tips and feedback on this topic, and the guys who have just posted back to you have covered a lot of good points and help.
Just two things spring to mind from me worth mentioning. First, satin or low gloss black would be the best way to go. Gloss black was never the original finish, but a lot of guys choose it because they personally like the look of it. That's a personal choice thing of course. Gloss finish also is easier to spray and finish work with from a spray painters point of view, and is far easier to maintain than a typical satin black finished panel. With gloss, you end up with no edge lines if you lay down a base coat/ clear coat application, which can be colored sanded and cut and polished later. However, satin black finishes are hard to maintain and keep looking good over time.They have a low tolerance to being touched or handled without being damaged. Waxing can bring on a shiney look, which is very hard to get rid of, and should be avoided. However, i have discovered an Australian made wax product that can be used all day without producing and gloss issues for any mat or satin finishes. It's called Bowden's Lazy Wax. It's the only product i know of that does not gloss up flat or satin blacks. It really is fantastic.
Second, i would recommend using Acrylic Lacquer satin black paint over 2K or two pack satin black if you are going the satin black way. 2K black is a more harder, durable paint finish over Lacquer, but the problem is that when you are spraying the 2k on you will 99% sure end up getting nibs or dirt particles in the finish as you apply the paint. When you do, the only way to remedy this is to let the paint dry, then block sand the nibs out, and then refinish the panel again.The problem is here, that when you respray the panel again, you will more than likely get fresh dirt in the job no matter. For the guys that can honestly say they have ended up with a completely nib free 2K satin finish off the gun, then all i can say is they have been very lucky to achieve that. However, when you shoot in Lacquer, you can sand and remove nibs or dirt on the fly, or as you are applying the paint. A coat of Lacquer can be dry or wet colored sanded around five to ten minutes after applying it. This means that you end up with a total dirt free satin finish without risking a crazy overloaded paint buildup.This is what i did on my '73 Nasa hood, and i ended up with a top looking, completely dirt free finish. I shot the hood about 5 years ago,and it still looks great today.
Hope that helps,
Greg.