yup, the wireless is definetely an interesting option. you'll pay about double to go that route and you'll still have to run a cable to the IR1000 as it is not wireless ready. Overall I would say using CAT 5 cable is going to be your cheapest solution. It's a no brainer if your house is already wired for ethernet. And you can run both at the same time, just hook the wireless access point into your hardwired hub.
There are really a lot of great options for home networking. A couple opinions:
1. If you are going wireless stick with the 802.11b standard, it seems to have the most momentum, I would stay away from the HomeRF stuff.
2. If you're wiring I would go with ethernet and CAT-5 cable. I have no experience with the networks that run over your phone line, but my preference would be a dedicated data network for performance reasons.

my 2 cents