I certainly don't think a '78 BMW is going to be sporting a rear disk. Also, trying to put BMW bars on antother bike is going to be a PITA because they are 22mm- not 7/8. If you do get BMW bars, you'll need to shim everything.
Personally, I've liked Superbike bars from Bikemaster as sold through Tucker Rocky. A little rise and pullback. The point of low bars is 2 things; it gets your weight forward, and you lean into the wind- which helps support your weight. Low bars and a fairing of anykind may look good to you, but it will be hard on your wrists and arms.