I just wanted to thank everyone who provided help and advice, both via the forum and by PM etc, it has been useful and I've learnt a great deal about the subject too.  At the moment, the choice is probably going to be Virgin Media as his girlfriend's mother uses them and has found them OK.  Will post if this changes or when I have any feedback.

I am under the impression that if there is already a virgin cable in your property / road it is alot more cost effective / straightforward to start up with them. Simply ring virgin and give the postcode for your property and their system can check the status, not sure about length of contract required to join with them, but isn,t it the case that with any telephone / broadband package company that even if you take out an eg 12 month contract that when / if you have to move address you simply take the contract / package with you to the next address you are living at and continue paying for the contract / package ? people have to move on occassion before a contract ends surely telephone companies can accomodate this situation ?