Knowing buggerall about the business of concept art other than what I see and read in magazines, it seems to me that those who stand out are those who draw well. My advice is to go to the place where there are talented artists who will teach you how to draw well.
I've been to an art school and talked to many other people who have been to other art schools and there is evidence that a course designed for, say, "Games Art and Design" does not necessarily mean it's the best course to get you a job in game art. This goes for other courses, i.e. an illustrator might be better doing a fine art course rather than a course specifically tailored for commercial illustration to become a good illustrator. You probably know this already so I'll shut up and let those who have experience answer.