Great idea and nice if you can do it. I was going to do the same a few years back with the many thousand images that I had but didn't know how to do the site and no one to help me so gave up on it. Pixabay is my site of preference now where I give away almost a 1000 images for free, and shutterstock is where I sell them. I've also got a 1000 images on flickr and lots of many other sites. I've got a few you can have if you want them..