As far as I'm aware, the manuals are simply the online notes printed out in book format. If you're the sort of person who really can't read a screen then just print out the notes. Unless you really, really like the feel of a book I can't help thinking that £550-600 is a hefty saving you could be making.
If you're decided though, as far as I know there's nothing stopping you taking the first module almost immediately, you just need to book the refresher course and exams. I'm curious as to what you think you're gaining by studying beforehand though? Just sign up earlier. There's no time limit to the course; all you'd be doing by studying pre-sign up is restricting yourself access to support and the rest of the online materials like questions and practice papers until you do sign up.