Social site for flat owners in a cooperative. This site will help the owners and board of directors to communicate

Social site for flatowners in a cooperative. Will use this for communication between owners, and make it easier for the board of directors to manage their job. Will have polls here so can decide what to decide in a convenient way. It will later probably be updates. Like to develope this using GIT, so more easy to install updates. Looking for long term relationship with developer company. If this project is done well, then this can be sold to other cooperatives as well. Need to create new design for each new customer and upload on new domain. Please feel free to tell me if you have better solutions on specific details in the project. I dont know at all what price will be for this project. I had to choose a budget price, but I dont know if I am wrong here. Jon Audun Thorsen