Both of above mentioned sites have very limited choice of performers that claim to be pressed on high quality audiophile CD.
In fact an audiophile CD not neccessarily have to be manufactured as an audiophile CD. Lot's of rare and modern jazz performers have their own small studios where they master their CDs near-perfect since they do care most of the time about how people will hear them even non-audiophiles.
Most of GRP, ECM, Concord, Avan(Japan) famous jazz labels have their CDs mastered near-perfect along with less known small private studios.
www.cdnow.com has probably THE widest choice of all kinds of music on CDs and all of them sold there are originals and not BMG or Columbia House re-manufactures.
For the rare CDs you can visit www.gemm.com that has a network of a private sellers-collectors along with huge stores all arround the world.