These are the ones I bought to use:
https://www.amazon.com/SANWA-GT-Y-Octagonal-Restrictor-Joysticks/dp/B06VVG936T/ref=mp_s_a_1_1_sspa?dchild=1&keywords=sanwa+octagonal+gate&qid=1599686929&sprefix=sanwa+oc&sr=8-1-spons&psc=1&smid=AAJOQX9WRG7SU&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyVDRFSVVYR05NOUg2JmVuY3J5cHRlZElkPUEwMzc1MjEzMjhCNVRZWDg0OTQwNCZlbmNyeXB0ZWRBZElkPUEwMjE3MzU2MzNNS09OOTFXUjBSRiZ3aWRnZXROYW1lPXNwX3Bob25lX3NlYXJjaF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl