@cory @Nazgulh @swenda
It's Recalbox's forum, not a youtube convertor one.
So i have to close this topic. Thanx 4 comprehension.

This is what I'm using, granted, it's PS3, but I'm really happy with them: https://www.amazon.com/gp/product/B07K1DMLS1/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1

Well, I ended up buying two more wii u pro controllers for a total of three. They really work great. They connect each time with no problem. I have not had to pair them multiple times. They require no changes to the default recalbox.config.

We have played several three-controller games such as guantlet, mario kart and super smash brothers and had no problems.

So the recommendation of this recalbox noob is the wii u pro controller. Be sure to get an OEM one - not a knock-off. They are a bit pricey, but the last two I got were refurbs from ebay and they look and work great.