You should be able to get an old WET11 fairly cheaply on ebay. The mk1 units are better because you can replace the puny wlan card with a chunkier senao unit and also you can easily mod for power over ethernet by adding a couple of links. You're more likely to find the mk2 units which aren't as hackable.

I would've thought 11meg would be more than enough for a rio receiver.

BTW, tonyc, I like your schematic, what did you do it in?