We have a number of rack mount kit options that will fit the TZ300, TZ400, TZ500, TZ600, as well as older products. There is no rackmount available for the SOHO model, and the larger NSA models are standard 19" rack-mountable and do not need a separate kit.
Most of the current mounting kits now include front facing network ports with short cables connecting into the rear of the firewall. There is also a place to secure the external firewall power supply.
For some of the firewalls there's an option for either the official Dell SonicWall mount kit, or the 3rd-Party version. Please check your requirements.