I finally got through to someone at (**insert name of offending company here**) to ask about our router order for the ATF. It turns out that although it is now out of stock and discontinued they had not bothered to let us know. So not only is the router used at the 40m not available, but the next model up in the range has also been discontinued.
I have therefore ordered this one instead as it appears to be the last wired router that linksys offer. I guess we could have substituted a wireless one but I'm not sure that would have gained us anything.
The specification list on the linksys website is pretty vague:
IEEE 802.3, IEEE 802.3u, IEEE 802.1p
Four 10/100 RJ-45 Switched Ports
One 10/100 RJ-45 Port for Broadband Modem
1 year hardware limited warranty
Lifetime award-winning online support tools
I'm assuming it will allow all the port forwarding settings etc that we need.