Similar position to you several weeks ago. After attending the Manchester Exhibition and seeking additional advice on pprune, i have registered with BGS. The clarity of the material is excellent and the general feeling of an establishment who are behind you to ensure you get through the ATPL exams is without question rather than just a number out their on your own.
I believe one of the most important aspects of distance learning is to ensure you have the sheer determination to put the hours in and get the progress tests done in a regular timely manner....good luck