Um. Personal recommendation is best if remotely possible - as above, remedial massage isn't the same as what (IME) the majority of regular massage therapists do. It hurts a lot more, for starters :)

Doesn't lizw see a chiropracter semi-regularly? S/he might be able to recommend someone. Might be worth asking on here - a decent physio or sports physio might also have contacts.

If you wind up going the Yellow Pages/online route, look for qualifications & membership of appropriate professional bodies.

(And if you find someone good, let me know - I'm seriously thinking of trying to convince the chap I'm seeing in Sydney to emigrate to London as he is *awesome* ;-) )