Design Extender does not offer fluid layouts at this time, we may be adding some fluid designs to the next upgrade, but there are no concrete plans at this time.
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.