Web portal creation for submission of customer data

Hi I need a web based portal where my customers can submit prescribed template data to me each month. They should be able to log in securely access a pre defined excel spreadsheet and save their monthly data submission to a central web based database. At point of data entry for client: There needs to be data validation rules and checks built intot the upload process. Certain data fields need validating to pre configurable data validation rules that will not allow submission of the data before fixed. Etc. The customers should able to see historic submissions, and also have the ability to see various graphical trend views of the data over time. There needs to be time stamp and recipt of delivery via email to predefined recipients. A PDF of the data submitted also need to be emailed to both me and the submitting party as another form of receipt. These PDFs need to be filed in the system automatically against the account in a monthly file structure. Central data store: I need a management system that controls who Can submit data, give them login credentials for ssl submission of data At my end, I need to see who has submitted their data files and who hasn't on a month to month basis. I need email capability to remind each party if they have missed their submission deadline, or it is approaching for example. I need clear reporting capabilities based on the data fields. There are approximately 15 fields, and each monthly record could contain up to 2000 data records, but most will be below 200. There will be under 50 individual submissions per month. I need export capabilities from the system to enable export into a data mart. You are quoting for the develment work to produce the system to hand over me so I can host it on my website. There is no rush, so I want it bug free and 100% accurate.