Well, I know this is a weird comment, but its the only thing I know about gaming laptop devices:
take the specs of a current Macbook, and find a PC version with that or better.
My macbook has had no issues playing any of the games I've tried to (It can even quadbox some MMORPGs and triplebox Perfect World with little to no framerate decrease.)
Its weird, but I'd consider it a good minimum benchmark for what you'd want in a gaming laptop.
Still, though, I'd suggest going to the top of your budget and buying the best machine possible because you prolly aren't going to be able to upgrade your hardware. Perhaps a little extra RAM, but not much else.
Also, don't mind Screen size. People act like its an issue, but I've never really found any real difference in visual experience between my widescreen PC laptop and this smaller (And lighterweight) macbook. Its mostly just a good way to add more money to the bottom line, if you ask me.
