Quality of Earnings for UK

I am looking for someone to review the quality of earnings of 2-3 opportunities I am considering in the UK. They range from £250k to £1.5m EBITDA and tend to be relatively asset light consultancies or property service businesses. Having bought 17 companies over the last 15 years I have always undertaken a review and forecast with my accountant but believe there is a better option by employing a specialist. Please could the Searchfunder community advise on: 1. What are the key attributes the review should include? 2. What information will the advisor require? 3. How much should I expect to pay? 4. How long would the process take? I am expecting this to be a fairly light touch process.