Well, I'm back online in the new house - with a lovely new 2Mbps ADSL connection. Upstream is still 256Kbps but that is as good as I can get for now (unless I want to pay for extra lines and start bonding ADSL connections).
Alan Irwin has pointed me towards the Linksys WRT54G router as the firmware has been modified by a number of people including Sveasoft. Looks really interesting - especially as you can boost the WiFi power and also have sshd running on the router!!