Thank you for the replies everyone. I am probably going to go for the two port Mayflash adapter. The Raphnet stuff does look higher quality to be sure, but it's also double the price and on back order.
@erk005 if you have a wiimote to plug the controller into to have it wireless, the mayflash dolphinbar is freaking awesome!! For wired the raphnet-tech adapter mentioned above works great. I have two of them i used before i got the dolphinbar.
Every game on the snes mini runs perfectly fine on a pi EXCEPT star fox 2. SNES9x2010 runs some areas and a tad poorly with choppy audio and slowdown. Snes9x2005 runs it smoothly, but a tad too fast compared to a snes mini. Not that you would notice if you don’t compare. The pi has a rewind feature like the snes mini but super fx games struggle with it.