You just received your Super Nintendo Classic Mini, and just found out the wires of the controllers are way to short. Also, you feel that wireless simply is the way to go in this day and age, even if it's for retro gaming.
You start looking for a better solution, and ended up here. Well done, because here is your solution. 8BitDo is making all kinds of retro controllers for use with PC, Mac, iOS, Android, Raspbery Pi ánd Nintendo's classic mini consoles.
The recently released Super Nintendo controllers from 8BitDo are available in both the purple as the colorful version, an can be bought for around $30. You will also need the SNES wireless adapter to connect a wireless controller to you SNES mini.
8BitDo controllers are not of a typical cheap Chinese quality. They feel solid, and at least of the same quality as the original controllers. And if you buy these SNES controllers, you can also use them on all your other devices.