Flying long range in our own aircraft sounds marvellous, but in Europe flying "VFR on top" is in my opinion, fraught with danger. Firstly, whilst you can calculate the cloud tops before flight, what do you do when you find out that the data supplied was inaccurate or out of date? Then, on an extended leg, how much time are you going to spend looking for holes to decend through if it all clags up together with the airspace which they are connected to (the hole) and how much time will you spend navigating? How will you guarantee you can descend at your destination? The METAR/ATIS for your destination will not neccesarily cover the area where you transit from "VFR on top" to just plain old VFR.
May I therefore suggest that you plan to go in the weeds but if you constantly find yourself doing these trips, you are probably loaded so spend your money on an IR and do things the easy way.