Looking for a Lightbox / Colorbox / Shadowbox plugin that supports comment forms

Hello WPMU community,

I know there are none on WPMU, but I am wondering if anyone has come across a plugin with some type of Modal box that has a comment form built in. Here's what I'm trying to do.

We have a theme that works similar to Pinterest. When a User clicks one of the posts on the main wall, it lightboxes the Featured Image of the post, and puts in the Title / Description (body) underneath the photo.

I am looking for some of plugin that serves as a lightbox (or any kind of Modal window) and comes with a "Comments" section to write / view comments on that particular post.

Has anyone ever come across something along these lines? Free or Premium are both fine, I'm just looking for a baseline to start with and Google has been no help.

Many Thanks for all your help!