Apacheboy,
The basic licence of a CPL is all you need to start earning money from flying. However, on its own, you won't get much of job. You would be looking at banner towing, aerial photography or following an FI's course, instruction (albeit a worthy career for many).
The main thing is that before you get your CPL you must have completed either CPL exams (I believe there are 9) or the ATPL exams (14 of them). There is no easy upgrade from the CPL's to the ATPL's without sitting all again. More importantly, there is only £300 or so difference if done by distance learning.
A CPL is better if allied to an Instrument Rating since you can then do jobs which require you to fly IFR in controlled airspace. However, you need to have more than the basic CPL exams. ATPL's wil cover this although you could just do IR exams (about £1100 distance learning). Again, this leans towards completing the ATPL's.
In short, do the ATPL's. It is cheaper than piecemeal exams and more importantly, covers all eventualities.
You could follow this route if you wanted:
PPL
Night Rating
Distance Learning ATPL's
CPL
Then you have the choice of straight into an IR and MCC course, or working as a FI/ banner tower etc. What I would stress is that there is minimal difference in cost between a frozen ATPL and a CPL/IR, but CPL/IR won't open many (if any doors!). Most single pilot operations eg. air taxi, glider towing have stipulated minimum hours that would cost you a lot of money to get to.
Obs cop