Develop a Program for Customer Data

Hi, I would like to develop a windows or mobile program/app that will accumulate information about customers. Each customer will have several sections of information accessible under their name. This will include Sections for: Section 1 Customers main details Contact information for different employees of the customer. (e.g. Foreman, Accounts, Project Manager) Section 2 *Site Risk Assessment survey (emailable direct to the customer when complete or later) *Job Risk Assessment (emailable direct to customer when complete or later) *Job Estimate Statement (emailable direct to customer when complete or later) All emails to customer should be PDF Section 3 Staff Job Sheet to include: Customer Details Date picker - Start time - End Time Area for listing materials used for Job (autocomplete entries from previous jobs when first characters are entered) Option to insert photos when required. (Direct from camera if possible or select from folder if not) Job sheet export as csv file for sage import if possible, and also as PDF for reports Drop down lists will be useful were practical (e.g. Contact information - Boss, Foreman, Accounts) *Risk Assessment options will be pre-filled but also be editable (e.g. Risk of fire due to "Chemicals" editable to "Solid fuel Stove") Also risk will auto fill when criteria is met (e.g. If risk type is 1 and risk level is 3 then description is "contents of cell F6") *Job Estimate Statement should be invoice style and include: Business Logo and contact details Customer Details Date Estimated Time of Job Main area for description of Job and materials required. Second Column for prices. Total Price Footer details (e.g. Terms and Conditions apply) The program or application will be installed on the most appropriate portable devices such as tablets (whichever is recommended Android, IOS or Windows based, although the option to edit on a PC would be good). Multiple employees (3-5) will use the program and will require access to all previous data on each device independently even if no internet connection. Any new data added each day should synchronize across all devices when the devices are connected to wifi. Formulas, blank areas etc should be locked and not possible to enter data into. Possible solutions could be MS Excel, MS Access database, Sql database, MS OneNote. These are some I have experience with myself. Although I'm not sure if a Database can be used on 3-5 devices at the same time. There could also be applications already created to do this that you know of that we may just need to buy and adapt or enter the data required to get started. This is the main initial requirement to begin but please understand this will vary during the project as it progresses. Some details will have been missed to begin, some ideas will change and better solutions will develop during the build. This means we need to be flexible with both changing the requirements and allowing extra time and money for changes. I am reasonable with negotiations providing you are reasonable with with the charges. Please give me your plan and solutions you have in mind, any problems that you think will be difficult to resolve and an estimate of how long or how much cost this project may be. Should we require buying special software to make this work I will arrange this before we commence. Thank you for taking the time to read this and I look forward to your proposal.