"pretty standard cable company job - wireless"
Let's see. The cable company gives you a modem that is ALSO a wireless router, and they give you two USB wireless N adapters.
So... you plug a Wireless N adapter into each computer, install the drivers, then have the Wireless N adapters connect to the Cable Modem that is also a Wireless Router.
Of course, if you can't find any Debian drivers for the USB wireless card, you could always go out and purchase a wireless card that you CAN get Debian drivers for. That would most likely be the least expensive option. (EDIT I'll go one step further. Here's a link to getting that specific network dongle to work with Debian.)
You could purchase a wireless Access Point or Repeater. This is a stand-alone device that would wirelessly connect to your Cable Modem/Router and could be connected to your switch. That would enable you to get the Debian machine online without having to use it's own Wireless Card.
You could also get a Wireless Etheret Bridge, It has a wireless card in it. You set it up to connect to a wireless router, and then connect it's ethernet port to a computer (or game console, etc). That way, you actually get wireless connectivity without having to muck about with drivers. You wouldn't connect one to a switch though, as it only hands off ONE IP address.
SIDE NOTE That was pretty darned nice of your cable company. All I've ever gotten from a cable company was a modem (that was not also a wireless router). And I've lived in all 4 corners of the USA, as well as multiple states in between.
So let's see. You've got information on how to use the equipment you've got... how to make it work with the Operating Systems you are using, and how to return to the functionality of the home network you once had. Sounds like everything is covered. Anything else?