Man, you guys have nailed the LP's to look for. The only others that immediately come to mind are Verve, Concord and ECM. The Verve are typically mainstream Jazz such as Ella Fitzgerald, Louis Armstrong and Billie Holiday. Even though many of these were recorded in mono or early stereo, they are lively, focused and intimate in their presentation. Pressings in good condition are almost certain to please, as these artists are impossible not to love.
The ECM label is comprised of modern artists like Keith Jarrett, Ralph Towner, Carla Bley, Oregon, and Steve Tibbetts. I very much like the ECM lineup, but would advise proceeding slowly if you are not familiar with this music. Some of the artists and performances are far from traditional mainstream jazz, and people tend to be either on one side or the other in accepting them.
The Concord LP's are not only finely crafted recordings with minimal mixing and equalization, they have a distinct sound. Once you have listened to a few Concord records, you will come to recognize their character. In addition to this fine format, some of the featured artists include Ray Brown, Rosemary Clooney, Jim Hall, Marian McPartland, Herb Ellis, Harry "Sweets" Edison and Joe Pass. These artists perform not only traditional jazz, but some surprising new sounds as well. There is always excellent location work on the live albums, especially the Concord Jazz Festival releases.
The reissue Fantasy products already mentioned, ( Pablo, Contemporary, Galaxy, etc.) are almost without exception, beautifully recorded sessions, featuring some of the most important Jazz artists of our time. There was a time a few years ago when this CA. based operation was struggling. During one summer, I remember them offering to the general public, new sealed LP's, 3 for $10.00. Every artist and label in their catalogue was available at this price, so a good number were sold. I found sealed copies as recently as a month ago, so I would certainly keep an eye out for these.
The Mosiac box sets mentioned were also of exceptional quality. Unfortunately, almost all that were ever produced are out of print. Worse, I see a trend were new releases are offered only on CD. The LP sets that were produced were typically limited to only 5000 hand numbered box sets. Some sold so quickly I lost my chance to buy some of the artists that I wanted. I did manage to aquire 28 of these box sets, and from that experience I will add that for Miles Davis, except for the "Plugged Nickel Sessions," you will do just as well with the Classic Records Reissues. As for the 45 RPM Classic reissues of Miles Davis, "Spain," just arrived at my home last week. If you are a Miles fan, you should purchase this title before there is a shortage.
Best wishes in putting your library together, I hope you find some of the joy in this music that my collection has provided me.