I've been searching online but can't find anything that specifically says it will fit my H3 that does not have the cut out in the rear bumper for the tow hitch. Does anyone know where I can get one?

 

There are many aftermarket hitch manufacturers.
Kurt, Hidden Hitch, Drawtite are a few. Look at online retailers like E-trailer or Autoanything.
They all bolt to existing holes in you H3 frame. They all sit below the standard bumper, so you will loose some clearance if you use your H3 offroad.
If clearance is an issue then your only option is the OEM hitch, which requires using the notched bumper or cutting the notch into your existing bumper.

 

Check out U-Haul for a hitch.
No cutting and no problems what so ever.
I think I paid $145 or so a couple of years ago - installed with a lifetime warranty.