Much of Kevin Moore's earlier work, as well as his Chroma Key project have many ambiance-driven music with tons of samples from old vintage movies, radio broadcasts, and much more. He has also done a few movie soundtracks that are completely ambiance, and while there's little sampling, it's there in bits and pieces. I'd start with Chroma Key though. Very soothing music with tons of sampling. The OSI project is more progressive rock than ambiance, but even they have some music that ambiance heavy that includes some sampling.