I think you are still fundamentally misunderstanding how multiplexed displays work.
You don't need any latches at all - the "latching" effect is done by the human eye! (the effect known as persistence of vision).

As I said previously, You just need to control the 7 (or 8) segment lines from the pins of one port, and the 6 digit selects from the pins of another port.
(all via suitable high-current buffers, of course)

eg, displaying "1234" on a 4-digit display goes something like this, only much faster:

I trust you can see how the digit selects are activating one digit at a time, and the segment lines carry the signals for the current digit.
Only one digit is actually active at a time, but you switch them fast enough that they all appear to be constantly lit to the human eye!


Faster, even, than this:

You could try making the frequency variable in your project, and observe how the digits appear to become steady as you turn the speed up...