Hello,
I'm trying trying to achieve the same as you, and I went down this route in the end:
I ordered the 802.11b
broadband router from ebuyer. It took a little time to arrive but they did keep me informed so I can't complain. It's a nice piece of kit for the price - it acts as a wireless access point, NAT router and hardwired hub. So essentially I have 3 pieces of kit in 1. Installation was a piece of cake and I had a home wireless network set up with a (hardware firewall to boot) in no time at all. In fact I'm typing this from the living room with router in an upstairs bedroom

I can now access the internet over my broadband connection from anywhere in the house without having to have my desktop PC switched on all the time. Sorted.
Prices of kit (including VAT) on
ebuyer were:
£11.74 - PCMCIA wireless card (quickfind - 52909)
£49.30 - wireless router (quickfind - 51436)
Hope this helps.
Kind regards,
Cyrill666