Thanks again for everyone's comments. I'll definitely be considering my options closely before making a decision.
I understand the concerns about my lack of the required experience to handle an aircraft like this. It does occur to me that taking my IR(r) course in an aircraft like this sitting alongside my instructor would be a decent way to start obtaining the experience necessary to fly such a plane.
Otherwise, how would I ever get the necessary experience?
If there were a decent aircraft available to rent in the meantime, I would certainly opt for that. But I haven't seen such an option so far. If anyone knows of something suitable, please let me know.
Incidentally, I don't intend to be trying to take the whole family on trips around Europe or anything. I expect most of the longer range flights will mainly be myself and sometimes one or two other passengers. But I would prefer to have the space available to take friends/family/colleagues for a short flight somewhere if the situation arises.