OK, well obviously some 2 leg network racks can hold more (hence the 100lb shelves), I didn't realize that. However, the linked rack above is made out of aluminum, so I would be worried about total weight on it. While monoprice doesn't list a max weight on the website, I bet you could call them and ask if they have that information available.
The only things I would really be concerned about is the receivers, Nuvo GC, and computer. The matrix switch, patch panels, and DTV receivers should all be pretty light.
If you live in a decent size city, you might try looking on Craigslist or E-Bay (do a local search) for used racks. You would be surprised how often they come up for sale and you can generally find a nice 4 post rack for about the cost of the new network rack. Of course if you live in a small town, the odds are probably against you finding one, but you never know :unsure: