Going back to the door I used a concealed hinge jig and drilled my holes 4" up from each end on the inside for my euro style soft close hinges. For the rear panel I cut it out of a piece of 1/2" birch plywood using my circular saw and a guide to 45.25" long and 22.75" wide...
For other LED fixtures, this statement cannot be made, because emitters are daisy chained together in a shotgun approach to provide output light. These light sources are now commonly dimmed, which we will find out if not done properly, it will not be the best for long term use. So beware...