Customizing Gallery for my Site

Ok, I want to put gallery into my site and avoid the style changing (opening up in a new window, or different looking page.) My site is set up like this: http://cpostudios.com Click on gallery, first album (only one), and it looks fine so far. But When you click on a picture, even if it is small, it stretches it so it no longer fits in the window. Is there a way I can either A) Make a popup system in Gallery where when you click on an image, it opens a popup with just the larger image? or B) Make it thinner to a degree? I think I'd rather have the popup system since I will have photography and short films, which will almost always be wider and often times taller than the space on my site.

Also, my next request would be nice to remove the login system for users. I just wanted to use a simple gallery system where I could upload pictures in a simple browser and have this system upload and organize them for me, like gallery does. But without other users. Don't know if this request has been made before.