Without Telewest or NTL your pretty much screwed for a separate line operator. Best bet is a BT line and an ISP. Of all the ISPs I've delt with over here Pipex has been the best. I still use their DNS servers even though I'm with BT Broadband now, as I find BTs a bit intermittent.
Have a look at Pipex. They do do phone as well, but I'm not sure if they do just tolls or if they can take over the line rental as well.