It's easy to miss in the first post, but that's covered...
it doesn't matter if the paint is glossy, as long as you finish it all off with a matte clear paint that dulls it down. but be REALLY careful. i've had the clear coat ruin the paint underneath when i've painted too fast, mixed brands, etc...
it's always good to test the reaction of paints on something other than your finished project.
one thing i've done in the past is to have a piece of plastic that i paint along side the armor. when i go to paint the next layer, i'll do it on the plastic first to see if it reacts well. not fool proof, but helpful if you don't know for sure what's going to happen. and even then there can still be problems.