Website & Mobile application Dev

I need to build a website and mobile app (iOS, Android) that helps in implement or consult in interior designs. The idea of this engine is to connect between internal designers from any ware and the clients (could be home users or project owners). the client will go through wizard which will ask him some of multiple questions (from 10 to 15 question) and that will give the designers the complete idea about the project time and cost. from another hand we will need to add multiple features which will help also home users to post some of the pictures for their home rooms, roof, doors ... etc and our system will have the capability to determine the dimensions of these rooms based on the taken pictures and provide the internal designers of the dimensions he needs which will help to have a complete idea about the project cost and time. the application will have multiple features like: online payment integrated with apple store and android google play and also through web online payment (Visa, Master, Pāypal ...) also it will have dimensions reader, and isolated interface for client, designer and the admin. there will will have capability to store the design files in some multiple formats like PDF or Images .. and be multiple sections of the design categories which added in the attached pictures. the system so on. we need to build this system to be stable, reliable and expandable later as we need to add many features later. we need initial plan and initial cost please share your ideas with me how to implement and what’s the program languages you suggest in order to achieve these goals. looking to hear from you soon.