Programable Keypad
This page lists the best programble keypads.
Ultimate Hacking Keyboard
If you want the most powerful programability, software works in {Windows, Mac, Linux} , most easy to use software, and 63 programable keys, get Ultimate Hacking Keyboard.
koolertron
For general purpose and not expensive, the koolertron is the best. Only flaw is require Microsoft Windows or macOS to program the keys.
HUION Keydial
Elgato
If you want display on the keys.
Genovation
Sturdy build, but the software is stuck to Windows 95 era. And Cherry MX Switches black, require heavy key press (60g). Otherwise, classic best.
Max Keyboard Falcon-20
x-keys
The x-keys are overly expensive.
Power of Keypad
Infinitton Programable Keypad
This came out in 2018-04.
Full color LCD display for each key. 1 year warranty few amazon reviews yet, but so far pretty good comments.