Unfortunately, I can not advise on recommendations for body/paintshops in your area as I live at the other end of the country.
However, for a complete body respray, the cost will depend on the quality of job you want.
Do you want to mask up or remove as the price difference will be considerable?
Prices will start at £2000.00 upwards for a respray + your rust issues.
A quality job, minimum of masking and fixing the rust may be circa £4000.00.
AS I have said, all boils down to what quality of job you want and how much you want to spend.
Talk to a few shops and get a feel of what you are up against.