Fantasy character art

Has anyone had art of the characters in their book comissioned?
I'm thinking to have it done when I release my book and use the pictures to promote my book by having weekly/bi-weekly character reveals/announcements.
I'm just not sure where to start looking, most of the recommend threads are a bit more general, I'm looking for fantasy style characters-a slightly more specific request

Well it would give more material to actually put up on my website, rather than just a description of the book.
Having the characters pictures and bios that people can see.

Taylor Anderson has something similar for his Destroyermen series with pictures of the races and creatures as well as some background info that you don't get from the books.
Like the Grik are bipedal, sentient descendents of raptors.
He's also added pictures of the ships.

I also have flags for each of my nations, but they are much easier than drawing characters. I have rough versions of the flags done and it shouldn't be hard to improve on them much