Capital Gains Tax

Hi, the laws keep changing both in France and the UK - can anyone recommend an accountant who would be able to advise me?..

After 5 years living in France I'm thinking of returning to the UK. I have a property there which I have owned for 16 years and rented out for the last 7, and am confused about whether it is better to sell it while I'm still in France or wait until I get back from a capital gains perspective.