shizzle,
From what I understand a standard inverter will work fine. There are several other posts of people using them. Check out the
MacCar threads
However, next month we'll be introducing the P1900, a DC-DC retulator which is designed to power the Mac mini and includes a startup/shutdown controller, and a secondary power output for your screen.. You can read more about it and the cable splicing that will be required
HERE and
HERE.
Good luck!