At this point there would be no reason to think you wouldn't have to pull the engine no matter what. With the damage there that will be inevitable, even to just change the piston if the bottom can be salvaged.
Now, personally I'd pull the heads (both of them) just to quickly see what the top end looks like. I sort of like dissecting things just to get a good look. You'll be able to see the tops of the pistons, and if that one is trashed, you'll be able to see if it damaged the cylinder. If it damaged the cylinder then replace engine. If it didn't damage cylinder you'll still have to pull the rest of the block to replace that piston and see what the bottom end looks like.
Just my way of doing things. I'm sure opinions will vary.
Now, personally I'd pull the heads (both of them) just to quickly see what the top end looks like. I sort of like dissecting things just to get a good look. You'll be able to see the tops of the pistons, and if that one is trashed, you'll be able to see if it damaged the cylinder. If it damaged the cylinder then replace engine. If it didn't damage cylinder you'll still have to pull the rest of the block to replace that piston and see what the bottom end looks like.
Just my way of doing things. I'm sure opinions will vary.