It's expensive, and I think it's a crap deal for the designers, but 99designs.com is what you're looking for. Of course, no one's going to make you an almost exact copy of that, unless you're all prepared to tread some potentially treacherous copyright waters. (You could have it taken down for copyright, you do realize, if you use a cover that's an obvious copy of that design? It needs to be different enough that it looks inspired by it without being an obvious copy.)
Why not just find a designer online that does work that you like, tell them you want something similar and work with that one person? Most will make mock-ups of at least 2-3 concepts for you to pick from, and will revise until you're happy (within reason). And you can know the source of the stock images with a reputable designer.
People from sites like 99designs have been caught numerous times just grabbing images out of a Google image search. Bad, bad news.
Buying a premade or custom cover from a reputable designer is better for just about everybody, and will probably cost you less and help you avoid possible hassle later on.