You might do worse than ask around the microlight community.
The 2012 World Microlight Championships were held in Spain, and so far as I know all of the British team flew there and back. Being microlights they'd have had to be day-VFR all the way, and their performance will have been similar to the aircraft you're thinking of.
All the teams names are at
Latest News and most of them should be easy to track down as a fair number run flying schools.
P