Thank you to all who have offered advice to me. It was a useful exercise in showing how many variables need to be taken into account when deciding what equipment to,buy. I have had a number of scopes over the years my first one being a 200 P dobsonian. Having taken into account my wish list and reviewed the scopes that were suggested I have decided to go for the Skywatcher 200 P DS on the Skytee mount. It fills my brief for aperture, ease of set up ( not as heavy as a dod) and will allow me to manually track my targets. Also there are a number of scopes unavailable at the moment with a long delivery time. I was very happy with the views from the dob I had a few years ago and I know that my existing eye piece collection suits the 200 P very well.