Invest in aerodynamic excellence
I would buy a new Mooney Acclaim-S (243KTS @ FL250, 1860nm range, 20-22gph) for $595K.
If you want better economy then get the non-turbocharged Ovation 2 or Ovation 3. You go further more slowly (but still significantly faster than any other non-turbocharged single).
The Mooney offers better range, speed and economy than anything else out there - no question.
You will be able to cross entire continents without having to refuel.
I hope the doggies can cross their legs as well as you can because your bladder capacity will become the range limiting factor.
In addition to this it also has the G1000 all glass cockpit as standard (the one to have) and the GFC 700 A/P flight director. The glass cockpit is fully integrated (unlike the Avidyne).
You can also have (the only factory fitted FIKI approved) TKS deicing, TCAS, install the MT weather radar system if you want and you will have a proper mini airliner.
The 3 year warranty with the new aircraft is well worth having as is the 1 week residential flight safety pilot training programme.
Most importantly you will be flying yourself around between your homes whilst sipping fuel at your convenience with minimal overheads in most weather conditions and will be under the 2MT euronav limit.
I think you will miss flying the R44 though - are you going to keep the helo?
SB