TUMBLR expand post. Options

[TheZimp]

Hi guys! I'm looking to Tumblr as an option for my video-based blog. I wanted to know if there's a way to "expand" a post. What I mean by this is that on the index page, I'd like to display thumbnails of screenshots of my videos and when a user clicks on the thumbnail, it brings them to the post's page with the high-res video embedded from YouTube and the disqus or FB comments along with the description and title. I found a theme that does something similar but if you click on the video thumbnails it actually plays the YouTube video at the size of the thumbnail which, in my opinion, is a little small (ex of the index page: http://nonnamariatv.tumblr.com/ ). What I'm looking for is that when someone clicks on the thumbnail, instead of playing the video, it goes to the post's page where people can see the video in highres (ex of the post page: http://nonnamariaandfriends.tumblr.com/pos...raffaella-diana ). I hope this isn't too hard to understand! I appreciate any help I can get!
A.