FWIW, the dual diaphragm booster pictured is basically a re-pop of the Hemi booster. Smaller diameter (8" dual vs 9" single) is handy for clearance and the "dual" part gives more boost which is nice for harder hi-po pads... also smaller piston area aftermarket calipers.

I run a similar booster with OE 1970 "E" PB linkage and it works well. If I did not have the linkage already, I might buy a kit as pictured.