If you are looking for a "Cordless" solution, then the CS540 is great and can be worn over the head as well (but is convertible so other ways to wear in addition). It can also be used with the proper EHS cord to answer via headset if not at your desk.
I don't work for Plantronics, but have always had great luck with their headsets and my users have really been happy as well. There are many other solutions for the 8845 here;
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.