(ad:) Hardware Store Liquidation, Decatur AL, **February 2023** - Shelving, several heights, 16" or 22" base deck!!  paint shakers, widespan racks and MUCH MORE!!! (click here)

Jackson, Gulfport, Southhaven, Greenville, Biloxi

There is NOT a dedicated store fixture dealer in the state of Mississippi, but that shouldn't present a problem.

The first stop on a shelving search is always store fixture liquidation sales.

Try local classified like craigslist (website). Check you city and nearby regions.  Don't be afraid to cross state lines into major metropolitan areas.

The southhaven area might check into cities like Memphis TN, Nashville, TN and Little Rock AR.
Most regions in Mississippi, like Jackson or Biloxi, however, will bypass these northern areas and go straight for the major markets, with dealers, in Texas or Atlanta.
Try these nearby states:

Texas

Georgia

Kentucky