Thomas,
I did my theory course through the City of London Polytechnic 15 years ago (I know that's a long time and a lot has changed since), and they were absolutely superb. Did it all as self study but with an instructor/advisor on the phone whenever I needed one.
Passed all the exams except Air Law 1 first time at Gatwick, saved me a fortune.
Maybe worth looking into ? Hope this helps anyway.
Cheers,
NEO