Looking for per-post image management plug-in

I'm looking for a per-post image management plug-in. I'd like something that allows me to add and manage multiple images per post, that can store those images in an external directory, and that will allow me to import a large library of images when I get started using it.

I have hundreds of thousands of images I need to import, and I don't want to have to use the media library and have it try to display ALL of them every time I add to or remove an image from a post.

Any suggestions?