To be considered, part of a lighting project.
(1.) Room dimensions, you mentioned.
(2.) Ceiling height, distance between light mounting height and the display area, train layout.
(3.) Reflectivity of walls and ceiling. Paint, wall coverings, natural lighting, to be consider, in addition to light fixtures.
(4.) Desired light level at the display (Foot candles)??
(5.) Work lighting and display lighting can be different.
(6.) Type of fixture, LED mentioned, (Lumens) light intensity the fixture can produce.
(7.) Size of the light fixture, Some LED lighting can be supplied as flat panels, requiring minimal installation space.
(8.) Some LED lighting has the ability to be dimmed, not all.
(9.) Note that LED dimming and dimmers are different from incandescent dimmers.
(10.) Color of LED lighting. Different color options have been mentioned. Daylight, Warm white, natural, etc.
(11.) A good electrical lighting supply dealer has the ability to answer most of these questions, or put you in contact with a light fixture sales representative.
Best wishes with your project.