Just wanted to say thanks for all of the replies. I went ahead and got the standard Microsoft adapter, and it recognized the controllers immediately. Also reconnects after things go to sleep. Love it. Thanks again!
An update from the original post: The emulator works with both my HDMI monitors, both directly via HDMI and via a VGA or DVI adapter. MAME works OK. It doesn't work with the old Dell monitor despite trying the video modes in recalbox.conf which are supported with the tvservice command. I've tried other video configurations in config.txt too. I ran into problems with dual xin-mo joysticks on MAME with Recalbox so I've decided to stick to Raspicade for the arcade machine and use Recalbox with a spare monitor for N64 games.
I got it working, finally. I read the github issue more closely, and apparently you have to press a button on the second gamepad while choosing two player mode (Super Soccer) or the second player (Bomberman).
Symbolic Link !!!! that's the solution đ I'm not an expert so i didn't think about this, but it could works. Tonight i will try and i let you know. Thank you very much. I think that for the next release someone should add the feature for changing the path of the resources...