Well, I guess I (more or less) solved my own problem: The JETware (
http://www.jetwaremobile.com) extension seems to add a lot of control over and finesse to the Hands-Free profile on the PPC. I can now get to all of the contacts that I want to and they are sorted the way I want them to be. Also, although it's a little weird in operation, I can now get to Voice Command on the PPC via the car's voice system.
I hope this helps someone else!
Cheers,
Martin.