With the bars at 70 degrees (20 degrees between the bars, top view), you would have a pretty short life out of your bushings, as this would put a lot of stress on them. 60 degrees works good. 45 degrees isn't necessary to get the suspension working properly, but the top and bottom bars should be about parallel when viewed from the side. If anything, they should be a little closer to each other at the front, when viewed from the side.

Don't use a panhard bar with triangulated four-bars. They will fight each other and cause a bind in your suspension.