I have a volvo D2-55. put it in a little over 3 years ago.
overall, its a great engine, and now have 1400 hours on it.
As for access to parts, in my travels, East coast, caribe, and
the Med, its never been a problem, although I've not needed much
on this engine. the only problem I had was the electronic box.
this fees electric to the solenoid, and has the microchip for hours, etc.
this shorted out for some reason. it was replaced at another
volvo place, with a quick check of my electric system, no charge.

If I had it to do over, and I had the option, I may have looked at
kobota, as I've heard nothing bad about them, but the volvo has been
great.
Rickf