wix.com type custom webpage builder system

Hello, I need a system similar to what many free website providers have to generate different templates according to users requirements..they can choose layout, change images, change colors, change style etc.. See video from wix.. [login to view URL] only difference is we won't allow multipage website..We only need to support one HTML page development..that will make things little easier These are the options I want to provide 1. Users can develop 1, 2 or 3 column webpage 2. They can manage, add modules in every column 3. They can choose style - rounded, simple, spacious, 4. They can choose pattern - like background transparent grid, adding gradient effect etc 5. of course colors needs to be changeable 6. within individual modules, the can add images, text etc..basis HTML editor will do.. 7. simple drag and drop features like wix These are some main feature..We can talk about details later.. Preferably looking for someone who had previously generated such HTML template builder...Please answer questions 1. please send me link to builder you have generated or explain what you did in any similar project..If not, at least tell me what you understand and what are you planning to do. 2. What are the main skills that will be used in this project. 3. How many weeks/days you can finish project.? I have seen many generic web design application with this..I will ignore it if you don't answer above questions..