Wanda
A Google search for "exhibit walls" finds many commercial options in addition to MBA: Panelock, NFA Space, Sing Core, LA Wall, etc. I don't have first-hand experience with any, but have explored MBA Mila-Wall in the past. I don't know how the others compare in price.
Have done in-house systems, but had excellent in-house fabrication capabilities. It's much easier if you can attach walls to an overhead structure. If not components must be wide enough to stand alone, or always joined to form corners for stability. Also have experience with an L-shaped wall that has locking casters so can be moved around to change the gallery configuration. Everything is a trade-off: large and stable usually means heavy and hard to move; light and easy to move can mean hard to stabilize and easy for visitors to knock around.
An art gallery in Birmingham uses plywood or MDF panels hung from overhead pipe rails. They can slide the panels down the middle of the gallery-slide apart for a series of small panels, or together for longer wall sections
If you don't have in-house fabrication, you might look for a local theater. The techs there should have experience building walls similar to what you are looking for.
Good luck.
Mark
Mark Driscoll, Designer
Driscoll Design Inc.
1927 South Hull Street, Montgomery, AL 36104 USA
Phone 334-262-8047 Cell 334-294-6663