Either one of the two should be sufficient – I believe that two would be overkill!
However, I’m a firm believer that there really is no need for a study text!
A revision kit is an absolute MUST but then the course notes and video lectures combined with those notes (and endless hours of question practice from the revision kit!) should be ample material for you to attempt the exam with confidence
Is it too late to save the cost of a study text?
Of course, if you hit any problems that you cannot understand, post again on this forum and I shall get back to you