Magic Trashman has written a tutorial on how to padhack a Neo Geo Mini controller to DB15 (arcade/Neo Geo direct connection) and add a clicky microswitch d-pad to it. It's a relatively complex mod involving custom 3D prints, but MT has been offering pre-modified controllers for sale through Twitter.
Neo Geo CD Pad Repair Kits
Hardware Classics: SNK Neo Geo Pocket Color
NEOGEO mini (White)
NEOGEO mini PAD(White)
8BitDo NEOGEO Controller
8bitdo is making a wireless recreation of the Neo Geo CD Controller (it's got a clicky D-pad nub!)
Shop neo geo mini controller online with fast shipping and fast delivery. For xbox series x, controller shell is the same as the controller. Find pad
Mini controller mini pad gamepad joystick+ ABCD buttons for neogeo
Neo Geo Mini: The RGSH Test – Retro Game SuperHyper
Neo Geo CD Controller conversion
8bitdo bringing back the Neo-Geo controller. : r/Fighters
Controllers for Neo Geo CD for sale
Neo Geo Mini: The RGSH Test – Retro Game SuperHyper
Wireless Neo Geo CD-Style USB Controller from 8Bitdo
Is Analogue Making a NEW NEO GEO? 8Bitdo Announces OFFICIAL SNK Clicky Stick Controllers!
8BitDo NeoGeo Wireless Controller review - an exceptional recreation of an iconic 90s gamepad
Controllers for Neo Geo CD for sale