I have good experiences with the Speedtouch 546 and 516 (basically the
same model, but difference in number of ethernet ports). A 546 now
runs for about 2 years at my parents home without any significant
problems. It's got an built-in router, but with older firmware you can
setup a DMZ (forward all traffic to a static ip) or you can assign the
public IP address of the connection to your broadband router of
choice.
http://www.speedtouchonline.com/516_...?menuCurrPos=1.
By the way, I work at the Speedtouch support and I added this group to
my list on Google groups, to get some news on ADSL connections in the
UK