where can I purchase digital re-master cds

I am looking to find a place to purchase digital reamsters as well as high quality music cds (redbook). New and old artists
Elusive Disc sells XRCD cd's I have several and they all sound great. Good Luck.
In addition to elusivedisc.com, also try acousticsounds.com and musicdirect.com. Some of what can be found on any or all of these three sites may also be available on amazon. When that's the case, the amazon price will usually be less; however, when a new re-issue comes out that does show up on amazon, it often does not show up on amazon until a couple weeks after it shows up on one of the three other sites mentioned.
I'm not sure exactly what you're asking, but Amazon has a very large selection of cds. You would have to search artists that you are interested in and sometimes read the reviews to determine if the cd is a good quality remaster.

If you are looking for high res material, Acoustic Sounds and Mobile Fidelity are releasing a limited number of SACDs. Someone in Japan is releasing a lot of SACDs, which can be purchased as imports, but they are expensive ($60 each). HDTracks is releasing quite a few high res digital downloads. Hope this helps.