help with 1993 chevy lumina sedan, trailer wiring , whats needed

Hello, I am in a bit of confusion. I have had a type 1 hitch mounted so I can tow a light trailer for snow thrower or lawn tractor and the mechanic mounting it could not do the wiring.

I contacted three parts stores for a wiring kit and was told

1. there isnt one for that car
2. a 4 wire flat cable with connectors for .95
3. A wiring kit for .95 is needed.

Dies anyone know what this car needs ?. I dont want to blow up the electrical by using the wrong one.

It is a 1993 lumina 4 door with 3.1 6 cyl engine

As I understand it , its an issue of seperate brake/ turn signal bulbs or a common bulb.

thanks