I think if I was interested in turn signals/ flasher I would use the stock brake lights and just add a generic trailer adapter that most foreign cars use because they have separate turn signals and brake lights.
I don't really need turn signals but back up lights would be nice. Now that I've finished my front 2" receiver hitch I thought about making something like the Bison rear bumper but with lights built into it to protect them better. It would be nice to find a clear light close to the same shape as the stock rear lights.
If not I'm thinking of using the oval sealed lights that fit into the grommets like this. They come in both stop/ tail lights and clear. My idea was to use a piece of roll bar tubing and take a hole saw or plasma cutter to make four oval holes so I can recess them into it with a little welding.