Thanks to all for the continuing suggestions. I'm now at the stage of poring over charts and putting together an itinerary. The aeroplane will be a Gardan Horizon which I have just bought and I set 600m as an initial minimum field length before I had actually flown the thing; I still don't have many hours on it but I will be addressing that before I go anywhere; it's already cleat that it can handle significantly shorter runways so I have more flexibility than I thought at first.
Thanks again to all who have offered suggestions.
Happy landings