To prepare a professional study for developing a classification website, include the technical background by a professional

I would like to spread a brief about the feasibility study I am looking to finalize, the study should include everything about the web desire, the technical supporter will assist to finalize the study and to assist in the nigotiation of the technical options fits our requirement, like the platform, the coding ext. Website for classified trading, expected 300k users and 400k daily visit user may register and upload the ad, visitors may check the ad and products photos of the ad and contact the owner whether through website message and then notification email, or through the direct contact. Registered user will have control panel. There will be three payments gateways, prepaid cards or mobile provider code through message for charge, the third gateway is credit card payment. Categories are varies, and sub categories as well, we will use many templates and restrictions for filling up the details of the ad, there should be control panel for customizing and edit the templates. Ads before publishing should be approved by admin, there might be publishing to the text only without admin approval, but this will be optional. Admin will have control panel to manage and approve the photo and text, there will be a filter for photos to add logo to the photos. Additional matrix will be added to the classified add is the region, ads should be sorted in the general page by date, but search engine will shortlist the results according to search.