Building on of these from "scratch" is not as scary as you think, and has the advantages of ultimate customization.
Really, all you need is one repeating elevator shaft texture or photo, you can build in Photoshop and duplicate 4 times to make the shaft walls. Once you've made one section of the 4 walls, you can group that and clone the group, and repeating this, you can make as deep a shaft as you need. Then a door texture to make two doors with, in a separate door "group" Everything in such a project is just rectangles and right angles, not hard to assemble, really. And free, if you don't count a couple hours of your time.
Most of the "look" in that revostock example is achieved from the lighting, some particle showers, which Motion already has ready to use in canned form, and some camera moves. The type could be motion-tracked to the walls of the shaft, or "stuck" to them as another texture layer.
You CAN do this. You SHOULD do this; it's a great way to master Motion with a relatively simple project that looks more complicated than it is.
To help you visualize it, you could print out some sheets of paper with the textures on them, fold or tape them together, and use that to guide your virtual camera planning.