Is there any way to obtain recordings of all of the clical music that exists all from one site (CD or mp3)?

iTunes has a lot, and it's really reliable. The only thing is that I'm not entirely sure that every clical piece has been recorded onto mp3/a cd. If it has, not all sites I don't think will have everything, as there is just so much to obtain. But it wouldn't hurt to try iTunes and see if you find what you're looking for.