Best spray paint for my M1A1 Thompson

[Großdeutschland]

So u've prob seen my refinished G&G Kar98k, with that finished i moved on to my new King Arms M1A1. The reason for me doing this was the stupid white chalked paint of the issued factory markings ( i did not know of the full metal and wood version for $500, which has engravings as it should ) I have ordered the full wood kit online and one metal hi cap so the only diff between the versions is the lower receiver ( which i saw for $90 u.s. can be ordered aswell at a later date ) nd the engravings. So i disassembled and sanded it down to bare metal, i just want it plane black rather then the white markings so its been primed and cured for a week. What is the toughest spray paint which comes in a flat black and will take a beating and not chip ?

Thanx

[ThunderCactus]

powdercoat