Would you have any capital that you could use to live on whilst you get set up in business. I agree with the other posters, it is hard to make a full living out here. But if you are living where there are a lot of ex pats it is possible to get a bussiness going allbeit slow but sure at first. I would have thought that Sofia would be a lot more open to new ideas like alternative therapies, it is a far more developed area of Bulgaria than most of the small villages. There are quite a lot of businesses out there, big businesses, so people must have some money, especially the young ones who tend to have more disposable income than those of us who have families etc.
Just do a lot of research first. Or, maybe come over and give it a go, but dont burn all your bridges back in the UK, dont sell up etc. You can always rent over here and see how things go first before making any big decisions.