if you want the ability to crop the images, you should not be using the resize options of the Upload behavior, you should be using Image Resizer for this.
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.