I was able to change my rear shock by myself. One thing I should mention, the engine was out. I would think you would be able to change with 2 people, one holding the rear up while the other does the rest. The torque specs are in the parts manual under notes.
Getting back to the first ?, if someone spent the money & time to change the rear shock it must be a better unit than the stock. But then again, maybe the last owner was a poser.