This radio setup is what we use in almost every one of our builds her at HRD.
The TK-790 has been discontinued and replaced by the Kenwood NX-5700. These Pre-owned TK-790H radios are backed by a 1 year warranty from PCI Race Radios and are an affordable option for high power output.
Optional add on are the COAX cable and an antenna both from PCI.
If you are running a aftermarket third brake light with a COAX built in, then you will only need to add the antenna along with the radio itself.