You know opinions are like #$%*s. I personally love my big CB750 turn signals way more than in my modern bike. They are easy to see and that's what I want when riding.
If I were going to change the turn signals, I would surely fit those bar-ends turn signals, very cafe. On the back, probably something on the license plate bracket. I guess there are some aftermarket catalogs to look from. As I'm more of the stocker type I always look first for the original part, though I can make exceptions at things like bolts, nuts, cables and that type of things if original get expensive.
Raul