If the problem is still current why don't you buy a wireless router? In my opinion, it is easier to use and doesn't have a lot of cables which spoil the design. You will not have anymore problems with finding a convenient desk, cupboard, etc. Anyway, for other questions about router, you can check this site router-network because there you can find all the information about routers and I think that you can find the right one for you. I bought the best router 2020 after their advice, and I don't regret it.

Can you find a maker space with a CNC router? That's probably how these were made, and the easiest way to do this. Other than that you'd want to make a template for the router to follow, and use a collar on the router to follow the template, The round holes I'd do on a drill press. Making the template will be a fair amount of work. I'd drill the ends of the elongaed holes on the drill press than use a jigsaw to cut the straight sides, finishing up with files and rasps to get them straight. They'll need to be oversize of your final holes by the difference between your router bit and collar diameters. Doable? Yes, certainly. Easy? Not so much. Piece of cake with a CNC router. Watch some youtube videos on template routing. The good news is that once you make the template you can make dozens of the final product.

Although you may need to be sure the router is broadcasting both 2.4 and 5.0 signals, connecting any device to a wifi signal is a function of the device (DVR for the cameras), not the router. Some devices are not dual band and you need to make sure whatever band it's looking for is being broadcast. I have several such things, older equipment that's 2.4 only. Can you connect it via an ethernet cable directly to the router? I have several such devices like that too, ethernet capable but without wifi ability. Or, you can get something like an IOGear ethernet to wifi adaptor. You adjust the wifi settings on the little IOGear device, then plug in an ethernet cable from it to the device needing a "network" connection. The IOGear device handles that in lieu of using the device's internal capability (which may or may not be working). I have several of them for different devices - one, for an old network music player that's both Ethernet and wifi capable, but the wifi died and it's not near an Ethernet connection. Another, for a cell phone range extender that's Ethernet capable only but that I want to put in a more central location than where the router is. The IOGear device connects via wifi and supplies the signal down a wire to the ethernet-only range extender, which has no idea how it got the signal but it doesn't matter.

DNS is Domain Name Server (or System) ... an Internet subsystem that resolves domain names to IP addresses. ISPs typically have in-house DNS servers that are automatically assigned to the users connection. Google has public DNS servers at 8.8.8.8 and 8.8.4.4 There are others. Search for "public dns servers"