Thanks so far!
Yes the single vs twin is the biggest decision. I've flown lots of singles in situations that I'd rather have a twin with the family on board (one recently in NZ), but can that justify the huge financial penalty? That, I guess is my first dilemma.
With regards operating budget, I would hazard a guess at 30K Euro pa for fixed. I get recompensed for fuel/parking through work, so that is less of an issue.
When I couldn't afford to go flying I would never have predicted these tough decisions you have to make when you can!!