Convert an Excel Pricing Model to a Web-Embedded Price Quote Tool

My company is wanting to take an excel model-based pricing tool and convert it into an online app that customers can use to build their own quote for our services. Here are the specific requirements: 1) Functionality from the spreadsheet able to be recreated in the format of a web form 2) A submit button mechanism that will trigger an internal event from our side - This would be a form submit that will create a lead in sales force OR a formatted email to a specified email address. 3) The potential customer that is building their own quote with the app/tool will be able to review the form submit process for simplicity. 4) We want to be able to make an update(s) to this tool, as needed, in the future. Please ask if you have any further questions. Thank you! Mike