A male terminal cap does make the assembly taller. The assembly with the female terminals is shorter but the boots on the wires are larger in diameter.
So you need to find the combination that fits the best with the screen, the induction system or the firewall mounting channels.
I personally expect any changes in a Pantera made from the "original factory stock configuration" likely to cause a rebalancing of the "shoehorn job" the Detomaso engineering team originally did to make everything fit on virtually everything in the car.
I don't see the value of the Progression Ignition tuneable advance as a big one in a 351c.
You are pretty much going to wind up with a very similar advance curve as supplied originally by Ford. That puts a greater value on the Ford ignition system. Using the Motorcraft solid state ignition system eliminates the need of getting the dreaded access to the original dual point distributor.
You don't need AI to determine the best combination here to use. No one is seeing the glitz of the polished aftermarket distributor housing buried against the firewall and hidden under the screen.
In this case, ugly is beautiful.
I considered all of these alternatives years ago. My combination is a solid state Motorcraft with a stock distributor advance, a male terminal distributor cap and a Pantera-Electronics control box with a huge aftermarket coil. Mr. Haas it positively correct in every respect in this situation...and it isn't ugly either.
THAT IS the "custom special ignition" for the Pantera. Why keep searching? "Pilgrim, your search has ended".