Right. Night, IFR, Jet A-1, 400 nm return, decent autopilot, best ice-protection, 700 metres sea-level:
Lightly loaded Cessna Conquest I / Baby King Air / or what Adam said, Commander. Pay an experienced pilot to fly with you and keep an eye on you for the first bit. Turbines can actually be easier than complex piston twins, I found, anyway. (try the C340 single-pilot IFR, that's eight levers you're faffing with just for the engines and the thing isn't really appreciably slower around the circuit than a B200) In order for the project to become massively cheaper you'd have to axe at least the Jet A-1 requirement. If you did you'd have a welter of Barons, Senecas, 310's etc. to choose from, getting cheaper by the day they are, too. I also think that D42-thingy looks heinous, but then tastes differ.
Always fun, these 'let's choose an aircraft' threads!