You're probably looking at this rack series because they look like good value, which they are. I opted for the 18U one because at least in the photos it has lockable hard rubber casters instead of hard plastic ones. Not only does the rubber make them lockable but also won't damage floors as easily. Comes with nuts, screws, feet (in case you don't want to use the casters), brackets for supporting the mid section of gear (one pair for each of 18 units) and an Allen key.
The rack isn't 100% sturdy but you're going to fill it up with gear anyway so not a big problem. The packaging left a lot to be desired. The pieces were in separate plastic bags and there was only one layer of cardboard (a box). The big pieces had extra cardboard corners but that didn't help much. My unit arrived with a hole in the box where something had rubbed/scratched and the four steel sides were grinding into each other in transit. Luckily none of that minor damage showed when assembled.