They aren't mutually exclusive. I'd probably use image resizer to resize the image to create the thumbnails. Then you can use lightbox to display the large images with scrolling.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.