Coyote - probably any non-catalyzed metallic paint can be rolled on, the problem is when wetsanding it it will probably go all wacky on you. If you could roll it on and not worry about sanding it down to get rid of orange peel or imperfections, it would be OK. In fact I have some rustoleum aluminum color that I'm going to put/roll on an engine block, where I dont really care about smoothness.

I think someone in the past rolled on some metallic flakes, then did a coat over that, and the flakes were still visible but were not affected by the wetsand. Not sure who it was..