Wow. I found this beauty at comicartfans.com. It's the painted cover for the collected edition of Predator vs. Magnus Robot Fighter by Dave Dorman. The trade is one of the rarest and most sought after Valiant comics with a reported print run of under 2,000 copies. I believe it was only distributed internationally which makes it even harder to find in the US. What a pity because the cover is gorgeous.
Even this cover can't make the red mini skirt and white go-go boots not look gay!