Would definately recommend CAPT (Caledonian Advance Pilot Training). I'm sure that 100 % online isn't possible but with them you would need only 2 weeks of classroom revision in the UK. I think Bristol is the same.
You really need to be disciplined to do this as it is A LOT to study and A LOT of useless stuff, which doesn't help motivation
. I did the revision for the exams while working full time and I tell you it's a pain in the ... .
If you plan on doing the exams in Gatwick at the CAA, make sure to book well in advance as the spots in the exams are limited and they don't offer all exams at all sittings at all the times. I wanted to get it done in 2 sittings (one of 8 and one of 6) but that wasn't possible. Took me 3 in the end (one of 8, one of 2 and another of 4.). But passed all on first attempt
Contact a guy here called "PACO" he can tell you all about CAPT
Cheers