I did end up going with Middle Atlantic. I purchased from showmecables.com instead, though:

Slim 5 Series Equipment Rack Enclosure - 20 In. Depth - 37 RU

SH Series Zero Space Rackshelves - 20 IN Deep

I bought two of these Zero Space shelves for the 20" depth rack, though I'll probably get two more. I'm going to be buying one more of these Middle Atlantic Slim 5 racks, except at the 26" depth, which I'll also get two of the Zero Space shelves for. I'll buy sliding shelves for the printer and scanner, and after that, I think my gear will be sufficiently served by these Raxxess rack trays.

I was impressed with my first order from Show Me Cables. Most of the order took one business day to arrive, and the one straggler package arrived the following day.
SuperGrand UltraDeluxe (Plus Extra More)