"Off road" X pipe is catless. I'd think twice in running this on the streets, as it is a federal law that requires catalitic converters on cars. No matter what the local state laws are, or if there are no inspections in your area, federal law supersedes any local laws.
Difficult (illegal) to sell or trade a car in without its federally required smog equipment. Even with "as is" statements in a bill of sale, a new owner can come after you.
Keep your stock exhaust if you go ahead with this, as you'll need to re-install the cats prior to selling or trading in the vehicle.
Install requires enough space underneath to get under the car to remove the stock pipes and install these. A lift makes it a piece of cake, but with jack stands and a hydralic jack, it could be done in a home garage.
It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt.