Hi,
Now I have moved from ADSL back to Cable I no longer need the following item 
so it is available to a LUGger for the princely sum of 15 (+ P&P), or I will 
chuck it on ebay. 
Speedtouch 512v4 ADSL modem
Power brick
Phone cable
2x ADSL microfilters
2x LAN cables
I have used it in bridging mode myself and put a Linux based firewall behind 
it,but it does all the usual stuff like NAT, port forwarding and the like.
It's not a current product (the 510v5 and v6 replace it) but it works just 
fine.
Some links:-
http://www.speedtouch.net.nz/ST510v4.htm
http://www.dsl-warehouse.co.uk/product.asp?pr=ST510V4
Cheers,
Al.