What you're looking for is easier to find than the holy grail. I know that you said that you're willing to pay for your art, but if you're wanting artword comparable to Sam'n'Max or Monkey island in terms of bulk and quality, and including animation, then you are going to have to really pay through the nose for it.
Just out of curiousity, how much are you willing to pay?
Just out of curiousity, how much are you willing to pay?