Gareth -
yes and no. Yes they have a PCMCIA slot, but no, they're really isn't much of "stock" anywhere. Some places in the US sell them sporadically, but the only sure way you could pick one up is from Salton at $499 (US) or take your chances on eBay where I believe they're averaging about $250 to $300.
Read some of these threads and you'll see what people are doing with them. You can use the X-10 Firecracker module to control your X-10 devices...
Also, you might want to to consider that browsing on the ePods is painfully slow -- even with a broadband connection. The trick is to use Windows NT 2000 Server with Terminal Services, or Citrix; browsing is much more pleasant as the server is doing all the processing.