It's not a question of appreciating art, it's a question of copyright law.
Generally speaking, you shouldn't use such a photo without a license. If you know when the photo was first published, you may be able to determine that it is now out of copyright and so available to use freely. Otherwise, you should probably find another photo that you can license or that is out of copyright.
Note that I'm basing this on your mention that this is "for commercial uses". If your use were noncommercial, you might be able to make out a case for fair use.
I'll add that Chris Moore has a recent website with quite a few photos related to Van Gogh's settings (because of his latest novel, Sacre Bleu, which is sort of about Van Gogh), and you may be able to find a usable photo there -- and to license it from him, since you would know who took it and when.