Hi there
You could try:
http://www.workpermit.com/uk/uk.htm
Our work permit and visa system seems to be horribly complicated these days, with tiers and permits. I think you would fall into Tier 2, which seems to be the general route for skilled workers who want to work in the UK. Unfortunately, this means that you would have to have a job offer in place, which is not an easy thing to achieve when you consider that obtaining a work permit can take months. I think there is also an annual cap on the number of workers who can come to the UK under this tier up until 2014.
Essentially, you would need to arrange for a UK employer to sponsor you so I would advice that you contact some professional bodies in the UK such as The General Council for Massage Therapy, the Association of Massage Practitioners, the Association of Therapeutic Massage Therapists or the International Register of Massage Therapists. They may be able to steer you in the right direction and suggest some employers who have sponsored overseas workers in the past.
Good luck!