Online Slideshow of Wedding Photos/Selling them

I'm pretty sure if you create a new account with snapfish and dish out the login details this would work? Not sure though, or there might be a way in which you could create a "open" album and people could buy from that album if they have a snapfish account or signup (they are free)

I'm a bit confused, are you asking your guests to pay for downloading the photos to make back the money you paid for the copyright?

That's an unusual request!

Unfortunately, like you said, all the gallery sites are aimed at the pros and either take a commission on the sale, or a set monthly fee.

Have you tried a workaround such as posting a low res / watermarked version on Youtube or Facebook, then if they want the full version, they can PayPal. A more more time consuming but more tactful way of doing it would be to create a free site using Wix. They have an ecommerce add-on.