As mentioned on replies to some of your previous posts to have an easy conversion you need Multi Crew hours in a Multi Pilot aeroplane (in plain English an aircraft certified as requiring two pilots ie: not even a B1900!!!!) therefore you will have to do all 14 written exams, CPL skill test & IR skill test. You might get an exemption in having to do a MCC course if you can prove that the SOP's in your current job required two pilots....
As said before do the search function and also call a school such as CATS
http://www.cranfieldaviation.co.uk/ or others who will give first hand advice....
With regards to work, plenty of opportunities to get going the minute your JAA licence is in hand. Lots of commercial single pilot operators who would be very interested I'm sure. Also, TP and Jet boys.... I'd recommend you join BALPA (British Airline Pilots Association) or the IPA (Independent Pilots Association) to get operator lists and employment advice.
The whole process is not cheap, not easy and a PAIN IN THE A##.... BUT does reap a quicker reward than compared to Canada at present and can pay a LOT LOT BETTER..... However, lifestyle sucks in comparison...
Your call & best of luck
JG