A&A are now taking pre-orders for an IPv6 Capable Contrend router on their website.
http://aaisp.net.uk/broadband-accessories.html
(The actual model is the Comtrend AR-5382u
http://www.comtrend.com/es/links/79$product.htm)
The description from the A&A website is
"A small ADSL2+ annex M router based on Broadcom chipset, supports IPv6 and IPv4. Includes firewall, 4 port switch, WiFi and even a USB host port for 3G dongle. As pre order we cannot guarantee all features work exactly as specified, may need s/w upgrades.Pre order, supplied as received from manufacturer, expected late Feb 2011"
As they warn it may not have all it's features working out of the box, but once everything is sorted the £50 they are asking for it would seem to be damn good value (are there any other routers for that price which for example support a 3G dongle ?)