Custom webpage manager system like wix.com instapage.com type

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.. But we need a lot of different things, look the: [login to view URL] We need system like this, when the customer will can only EDIT our templates. 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..