You could use 2 ipac2 interfaces if you reprogram and make sure buttons don't interfere. I would highly recommend tu use the ipac4 instead. It's cheaper, and it will be easier to use for that purpose.
Have never used WICO joysticks but in general:
A 4 way joystick can move left, up, right or down. It has a diamond shaped restrictor.
A 8 way joystick can also move left up, up right, down right and down left. It has a square restrictor.