Can't advise on the conversion, call the UK CAA and get an assessment. It seems it depends on hours/type as to how much they deem necessary to convert your licence.
As for jobs, there are plenty for pilots with 1000hrs+ on anything. Your turbine and multi time would see you snapped up by a turbo-prop regional. The pay varies from terrible to ok (about £17000-£23000 for f/o's).
If you really are committed and spend several months 'hammering' the jet operators you stand a reasonable chance of a rhs in a holiday charter jet (757/A320)/ smaller jet schedule (146/737). Pay is better (between £20000-£40000)but it is not easy even with your experience. The low cost jet carriers are in strong competition at the moment, but they still want a 737 rating for employment, and they seem to be getting them.
My thoughts would be;
1 see how much it will cost to convert.
2 factor in the expense of moving etc
3 consider what that could get you at home in terms of experience/ job prospects
4 appreciate that a turbo-prop job on low-ish wages with a high cost of living may be the best you can get.
5 then decide
Best of luck with whatever you decide.
PP