Mark,

I use a Siemens C475 IP for incoming VOIP calls for my business. I have 3 hands sets in total. I have to say they work really really well, the audio quality is excellent and so far I have had no issues at all. My VOIP provider even gave me step by step instructions to get them working, but it wasn't too difficult.

Basically my system can handle 3 calls at once, 2 VIOP and one POTS. In general operation they are a little clunky and slow sometimes, but you can sync you address book between hands sets and there are other pretty cool features.

I would recommend them. I would be happy to forward one onto you if you can't find a source elsewhere.

On a side to the handset question, generally I find VOIP brilliant. My provider supports useful features like if I don't answer my VOIP line then all calls are transferred to my mobile so I never miss any business. I got to control all this via a nice easy web interface which I find very powerful. There are also lots of cool options on the handsets themselves of course.

Cheers

Cris.