A 2 stroke would be an easy swap. I would go with a 150hp Optimax salt water. For a new motor you will have to go through a Mercury dealer. Some dealers have 2-4 year old new motors that they will work a deal on. You will have to call around.
“The world will not be destroyed by those who do evil, but by those who watch them without doing anything” Remember what He has done and remember that He is not done yet! GOD IS GOOD