These are some pretty amazing pictures!
Has TDH ever considered getting a smugmug account to upload all the reference pictures to? (
www.smugmug.com) The costs aren't that much, and you can upload full resolution images to the galleries with no limits. Then the users can view the images at any resolution they want. All the resizing is done on the server-side of SmugMug, so all you have to do is upload the high resolution images.
If I'm just repeating something someone else already mentioned, sorry!