Well your propositions are quite challenging. :-D
I believe I'll have to practice LWCAD a little before tackling these ones !
But who knows ?
There is an abbey I want to make first (the abbey of Evaux-les Bains), but afterwards, I'll try Château-Frontenac, just for fun (but it will definitely take some time !!!)
And one day, when I really have some time and skills, I will try my biggest challenge in modelling :
The castle of haut-Koenigsbourg...