To mount that hitch from 4x4 parts, drilling is not required. It's a Valley hitch (same company who makes the OEM hitches). The only difference between that hitch and an EOM hitch is the OEM has a rubber piece where the step is and it has a bracket for the wire harness.
With the one from 4x4 parts, the step is still there, it's just metal and I would suggest drilling a hole in the back of the bumper and mounting the plug there. Before black panther's site went down, there was a nice how-to for doing this. I think all it takes is a 2" hole saw and a normal drill bit (forget the size) for the bolts to hold the plug in. It looks good and is more practical.