IP5000 works fine.

Be aware the IP5000 is PoE only, there is no option to purchase a PSU. It also isn't expandable.

The IP6000 and IP7000 have an optional PSU and can take external mic's if used in a large room/table.

Conference calling from these isn't as simple as the analogue, as you can't (at least last i tried) use the conference key on the unit, you have to use hold and the conference feature code.