I looked at some guides for ideas and was hoping to find a ready to go solution but nothing seemed perfect for our use case. Good quality photos for keepsakes was a primary goal so I used this as an excuse to buy a DSLR (which still ended up being cheaper than renting a photobooth for a few hours would have been). I chose to code it up in Python since it seemed like the best candidate with plenty of libraries that could handle what I wanted. I chose a camera based on what devices were supported in gphoto2. Specifically, I chose a camera that supported live preview which allowed our guests to frame their photo better. I answered the question about connecting the camera in another comment but the tl;dr is that it was connected via USB and all communications were through the python app I wrote using the gphoto2 library.