Print the whole thing on a clear or white backed digital vinyl and mount it to acrylic.
illuminate with LEDs sourced from Amari or similar.
If you have a CNC router and work with acrylic, you could route the face and returns and assemble like an acrylic letter/lightbox.
Use a folded aluminium with 1-inch returns for the rear tray and secure with screws in from the sides.
Make sure the face of the tray inside is white. A bit like a biscuit tin lid, but the large returns attached to the face.
it’s not big and you could do the whole thing in-house relatively quickly.
the only tricky part for you may be the corners with the radius, but I would give a price with and without the radius, you will find them may just go with the square corners if this is not following a brand etc.
as for their request of easy remove and move location.
Fitting and removing is easy other than the electrics. you screw the tray/pan to the wall and slip the acrylic face over and secure with screws. do same in reverse to remove.
just leave them 10ft of cable coming out the back and Let them arrange an electrician to hard wire it into their mains, as you will not be covered anyway. so will be the same exercise for them if they leave.
alternatively, you could outsource the whole thing.