A hitstick is when you have an arcade stick but with extra buttons that allow you to use the buttons and joystick for movement.
The Modulus is a modular controller that allows you to choose its layout and shape from a list of presets or something completely custom.
The DoubleSalt is a hitstick with directional buttons that are more slanted than usual, and three of them are smaller than the other buttons.
Okayama Tactical Gaming's Ikaruga is so customizable that you can even order it with the unusual layout depicted in the picture.
The Kurogane by Okayama Tactical Gaming has some pretty interesting custom options, such as an optional slope.
Brian Hill Woodworks is an LLC that offers wooden cases in lever or leverless format that are finished with Danish oil.
Doesn't this controller remind you of Tetris? And No More Lines offers many other layouts—sometimes with all buttons (or even a joystick)!
You can buy Akekon Dojo's DP-5 regular or mini version with 11 or 13 buttons and at least three color options.
If you were to buy the DRM JS 30's, buy it for its two extra buttons—as well as one touch opening from its bottom.