I have also been recommended Andrews & Arnold - they have some guy who posts on alt.internet.providers.uk and uk.telecom.broadband and they know their stuff. Pipex is the cheapest of the large ISPs.
Our exchange is getting upgraded on the 22ns and I am getting hooked up on the 28th Unfortunately I have 6 months left on a £23/month ISDN contract and BT are the only people that pay off your ISDN contract if you sign up with their ADSL service for 12 months. (yes, very "strange")
After several years with a modem, a year with 2-way sat and 6 months with ISDN it will be a huge relief.
Gareth