I would get "factory" harness (for tow lights) if TV does not have one and wire trailer according the connector on the TV and "accepted standards" for connectors found at almost any trailer parts source on the I-net...
Old school was to just connect a extension of tail/stop/turn light from back of TV to trailer plug.... With the newer wiring systems on vehicles with everything being "current sensitive" and computer controlled most vehicles have provisions for "plug in" towing light harnesses.... To go that route makes life so much simpler.... Most towing wiring harnesses either have provisions for converting from a 3 wire (filament) tail light system to a 2 wire (filament) system with built in converter, or connect to existing wiring harness provided from factory with provisions for using 2 wire filament tail lamps....
Converters come in all different flavors from ones the work just a few days or weeks and fail (went through 2 before finding one that was "good") to ones that are totally bullet proof.....
http://www.etrailer.com/Vehicle-Wiring/ ... 1995302306
(just buying converter alone will probably cost as much as this harness with converter)
MY first thoughts would be to go with factor style harness, its more expensive but possible more fool proof.... If that is not you flavor then yes add in a converter box.....
Dale