Donations to picture/album owner: shopping cart. donation module or ?

Hi. I've been a Gallery user for yonks, using it for my own personal photo albums.

Over the past two years my wife and I have gotten involved in the companion animal rescue and welfare scene. I have an idea for a website something along the lines of Petfinder only which lists animals that are in need of help, financial or otherwise: those that need surgery, have ongoing veterinary care, or just need someone to sponsor them to pay for their food and upkeep in whatever shelter they're in.

I can't find any f/oss web app for what I want, then this morning I thought "Aha! Why not use Gallery?" But what I'm going to need is the ability for guests to make PayPal donations directly to the photo's or album's owner, tagged such that s/he knows what dog or cat the donation's for (e.g. the name of the picture.)

I've never used Gallery commercially, so I don't know if its own Shopping Cart module can do what I want: I know that its cart is actually intended to let people buy pictures, but that's all I know about it. Can I make Gallery 3 let people make donations to individual needy pets?