Use a 4 way if your going with a non-switchable type.
BUT, that depends on what your focus is, Pacman, DK and others "freeze" with a diagonal signal.
I personally LOVE the ulimarc magstick plus with a ball top stick.
4/8 way switchable one, above the panel at that (pull up and twist to change).
I like that when this joystick is in 4 way mode, it has a diamond restrictor plate.
So it feels just like the dedicated 4-ways used in the original machines.
That said, as they ship they have some stiff microswitches...
Trade those out for some standard cherry micros and it feels much better!
One other thing, the magstick isn't for you if you like a lot of movement.
It is slight of throw, works great if your fitting a Galaga panel as you can use the slotted hole without messing it up!!