After talking to rms he convinced me to go to 68-72 B body drum brake spindle. They can be had cheap as no one wants them.
If it is a dedicated drag car, wilwood makes a drag brake kit for this spindle and this spindle uses the large ball joint. Since you like the heim joints, qa1 also makes a 1 inch longer super low friction adjustable ball joint that improves the camber geometry.(wheels don,t tilt inwards on a wheelie and rms makes an upper control arm
With the heim joints as well. Its the way that I went. I also put in grease able lower control arms with a white nylon bushing and rms heim joint strut rods to like you said, really make it work. Oh and also the Calvert front shock, a real 90/10 shock, these babies extend real easy, not like my old Lakewood 90/10.