Played out topic but tired of BS answers...

Ok, bitch me out, I'm sure some of you are tired of this. I thought I had my mind made up but idiots keep steering me the wrong way. I want the suede, satin, flat black look. Doesn't matter. Primer can allow moisture to seep in, what's the best way to get something that will last and keep the moisture out? I've heard about putting a flattening agent in clear coat and cover the flat black with it. But I'm no expert painter so I turn it over to you....