For a DECT/VoIP setup it is hard to beat Panasonic. Although the slim and almost double the price KX-UDT121 offers more features and a much smaller footprint in your hand (footprint in your hand?) the TPA60 counters with easier setup, standard AAA rechargeable batteries, and a more common form factor for users of cordless phones. There is a plugin for a wired headset. This is also available on the more expensive KX-UDT121 but that handset also offers Bluetooth. Unless you really need Bluetooth and carrying a 30% larger and heavier headset will ruin your life, the KX-TPA60 offers great bang for your buck. Note that these phones require a base station to connect to VoIP/SIP - if you don't know what that is, you don't want this model Panasonic! The Panasonic TGP600 base will function as a standalone VoIP phone system with up to 8 handsets/desk (TPA65) units or you can configure to a PBX with each phone acting as an extension. The TGP600 is sold alone or paired with a TPA60 which is the way most people will buy their first one.