Scoutfinch, finding an IVF clinic/doctor is, as TheApprentice says, so much more than league tables. They are pretty useless - like school league tables IMO.
When we found out we needed IVF 3 years ago, we first went to the HFEA website and sent off for their book on clinics and researched questions to ask etc. We're lucky in that we live in the SE so have loads of clinics to choose from, including all of the London clinics if we'd so wished. They will want to try and avoid too much travel if they can, but it depends where they live and how much choice they will have locally. There is so much to consider when making your choice.
We decided not to go for London clinics at the time cos of the stress and expense of travelling into London regularly (there are alot of appts involved in IVF). We narrowed our choice down to two clinics - one with a success rate at the time of 45% and the other one with a success rate of 26%. You'd think it would be a no-brainer, but actually we went to visit both and it really made us think. The more successful clinic was packed, so much so we had to sit in the corridor, the doctor I saw was arrogant and rude, and I felt totally unlistened to and dismissed. I also found out that all the treatment would be done by the nurses and I would never see the doctors except for egg collection.
The other clinic, by contrast, was much quieter and the staff were far more friendly. Plus the doctor was female and absolutely adorable. She explained that their success rates were low because they had a v high proportion of women in their 40s, whereas I was only 33 at the time so had a much better chance of success. I would never have considered going anywhere else and have never regretted my decision.
A couple of useful links for you:
www.hfea.gov.uk/
www.fertilityfriends.co.uk/forum/index.php?board=139.0
I wish your friends all the best, IVF is a tough, tough road.