I think it would be very hard to get sponsorship from an airline, that was my plan before september 11th but that won't be happening for a few years now. You could get sponsorship for a PPL though. As already said you could try the Air League, I think they have a 20 hour sponsorhip going and you could also try for an RAF Flying Scholarship which is also 20 hours. I know you said you cant join the RAF but you can get the scholarship without commiting to anything so maybe you should try that.