I don’t keep old syllabuses but from memory I do not think there have been any important syllabus changes.
However if you are watching my free lectures then you do not really need a Study Text. The lectures are a complete free course and cover everything needed to be able to pass the exam well (and are up-to-date for the current syllabus).
However you choose to study, then most important book is the Revision Kit because it contains lots of past exam and other exam standard questions for practice, and practice is essential for passing the exam. (And it would be best to get a current edition of it – if you get one from BPP then you get a 20% discount by using the link on this page.)