Remington has made left handed versions in the past, so I would look for a used one of those. I have been shooting right handed versions for 47 years with no issues. If you like Benellis, have at it, but no way do I think they are worth anywhere near what they want for them, plus I don't like the feel or the recoil. Proof that marketing does work however.
You can't buy just a receiver, because a lot of other parts are different too. Some people shoot a right handed gun and just swap the safety over.