I don't know where the joysticks can be obtained. I scavenged them from a piece of equipment i found in the electronics waste at the local recycling station. It was some kind of controller box. From the labeling on the (obviously homemade, but pro looking) box i gather that it's original purpose was related to film / camera work of some sorts.
But anyways they are really a bit too big for the AE case, i had to stand the bus connector on one end and fiddle a bit to make it fit, and still the panel is bulging a bit in the middle.
And ergonomically, having two joysticks in a 2U panel is not ideal. When order my two new cases, one of the old cases will be re purposed for some kind of "controller box" with one joystick at each end, and some other frequently touched modules in the middle. When i move them i will try to sand a bit of the bottom of the plastic enclosure around the joystick assembly to reduce the height a bit.
I bought the same model at a Kyouritsu store in Osaka, Japan.
they are a bit big for the AE format but I am still tempted to put some in.
The tiny joysticks used in consumer electronics are pretty good but you need to dismantle them to remove the centering springs, after which they feel a bit loose. I am thinking of ways to add friction so they remain in place and don't flop around.