2 player pc stick remapping question


So, I am almost done building my 2 player arcade setup. I am using the IPAC2 to convert the buttons into keyboard strokes.

I started buying some games on steam during the summer sale and a lot of them require player 2 to be on a separate keyboard or control pad (separate usb plug). Has anyone experienced this and figured out a work around to convert some keyboard buttons to a separate usb controller?

Also, does anyone with a 2 player arcade cab or stick have any recommendations for steam games that can be remapped in game to work with just 1 keyboard?