I just ask : Locate pristine vinyl (generaly 78s) by Southern Region to fulfill what was requested.
Not CD's but REAL vinyl 1950s ( Very , Very Rare to Impossible) , 1960s (Rare to Difficult) & 1970s (available but hard to find). Stop barking and go to work locating vinyl, real race/blues vinyl. You will find that the Southern Huricanes since '03 have made locating first pressings of race/blues records almost impossible because most of the truly great Southern Collections have been destroyed by water.
Should you be asking what blues are available on CD ,THAN, that's a different quest. CD's centered on (1950-60s) can CERTIANLY be found and what may still be found on vinyl (late-1960-70s) then you have a chance.
I personally collect music from a 80sq. mile area in State of LA. Most of those towns were under water and music from the initial printings is rising in value 10 to 1,000 X .
For now, CD's are the way to go, unless you demand the 78s from the 1950-60s. And should you be that person you need don't need us but rather an advisor who can LOCATE and recommend what's available and at what cost.
Lastly, a Tip: For genuine early blues try Smithsonian Records that sell records (re-recorded) from the Libary of Congress Collection, one of the most significant collections of race/blues records in the world , next to Claptian & Plant to mention a few. In the USA on FIOS the Smithsonian Channel will be showing a history of race/blues music starting 11/18/08 that most probably will be sold on DVD & CD. All the best.
PS As a fellow who grew up in a Southern City , I recall we kids throwing tin cans in a alley at night ... oh how the junk yard dogs barked. Some of you got to lighten-up.