Theres that many Enta resellers that it would be impossible to list them all on the site..
although you will find plenty of references to Enta if you look.
UKFSN, ADSL24, Aquiss seem to be about the most popular.
I saw elsewhere that you were looking for an "unlimited" provider which is nigh on impossible unless you can get Be.
However... if you are thinking of Enta watch out for their ALT system.
http://www.kitz.co.uk/adsl/caps.htm