I have in the past worked on a self employed basis for a flying school.Initially I had problems with the man from the national insurance office (two of them turned up at my parents house demanding to see me when I was working 200 miles away) however the tax man readily accepted my position as self employed and the NI then followed suite.Get yourself a good accountant,mine cost about £150 for the year but he did an excellent job.All my training the previous year was offset against my tax and in my first year I earnt c£10K and didnt need to pay any tax.
At that time I got £10 per hour but that was some years ago.
Being self employed worked for me however there was of course no security if your main source of work dissapears as mine did.
Good Luck.