I mis-read the extension specs.
So, I would go with this 2-1/2 Curt Receiver and the 2-1/2 extension.
Curt Trailer Hitch Receiver - Custom Fit - Class V - 2-1/2" $256.60
Specs:
Receiver opening: 2-1/2" x 2-1/2"
Rating: Class V
Maximum gross trailer weight: 20,000 lbs
Maximum GTW when used with weight distribution: 20,000 lbs
Maximum tongue weight: 2,700 lbs
Maximum TW when used with weight distribution: 2,700 lbs
Limited lifetime warranty
I installed a 2" Curt receiver on my Dodge. Easy no drill install. Mine allowed me to retain the original OEM receiver so I can fabricate a double truss if I choose to do so. I have a 48" extension I use to flat tow (no tongue weight) my Samurai.