Trex,
the 9 subjects are as follows, I am doing them through CATS and these are how they are broken down with them and so far it seems possible to do them over the course of 6-9 months, but I believe you can stretch them out over a longer period if you like, one thing to bear in mind is that, unlike the ATPL's, you can only do the CPL exams at CAA HQ Gatwick and no other exam centre :
STAGE 1
Human Performance & Limitations
Air Law & ATC Procedures
Operational Procedures
VFR Communications
Meteorology
STAGE 2
Principles of Flight
Flight Planning
(Performance, Mass & Balance
& Flight Planning)
Navigation
STAGE 3
Aircraft General Knowledge