Thanks for the answers!
As JAN requested, yes it will be VFR and I'm not willing to do VFR on top... if it can be avoided.
Legs of 300 NM and "interesting" means beautiful scenery, good restaurant, museums, good facilities or special friendliness to GA... courtesy car.... (although I never saw it in EU)
Fuel is not an issue, MOGAS or AVGAS are fine.
Thanks for the museum's suggestion!
High grounds are a possibility, the planning is the planning and I will prepare different routes depending on how the weather might be in 2 weeks time when I will be flying. Moutain airfields in the alps sound really nice and I expect to cross some valleys in the Alps and Pyrenees, but I'll not get in there before knowing the engine and performances of a plane I never flew before. I have sufficient experience in aviation to see the danger of an environment I am not used too, and it feels better when you have 675Hp like I had in Africa flying in hot and high fields. Now we are talking of a P2002.... slightly different situation.
Brener Pass..... uffff looks amazing! Its going to be difficult not to go there now that I saw the pictures... Thanks for the tip DAR!
La cerdanya was already in my mind, but also LECI looks nice, Good tip for the pool!
Tagron, thanks for the Lake Constanza field. its a good decision point to evaluate weather to continue or not.
Thank you all for the ideas.
It should be a database of common knowledge of this things, not just the Accukwik "it has fuel or not" database.