I use a modern electronic VR that looks just like the original and bypassed the ballast from behind with a solid piece of 12awg copper to supply full voltage to the Pertronix III stuffed in the factory style dizzy. Hard pressed to tell it is not stock and no extra wires short of the +12v feeding the Pertonix module. It is heat shrinked with the Neg. to hide it.
Most any, unless you find a NOS on ebag or something, WILL be solid state. There used to be a "heavy duty" version but they don't seem to be available in some brands anymore
The part no. if you can find them is Standard Blue Streak VR-128 or Echlin VR1001, looks like this, hooks up the same as the "up through 69" VR
Another good way to go is to buy a "square back" (73 and later) so called "dual field" (incorrect term, they are "isolated field") and then add just one more wire to use the newer 70--and later VR
Looks like this.........and mounts link your old one.......