I need a web application from scratch. It will be operational software for mortgage lenders. It will be very AJAX (desktop look and feel), XML (40-60 forms), but will need a little advice on the base programming language (.net, php, ???), SSL. The main features will include: -a couple of custom mortgage calculators of which I have all the formulas. -calendar engine that will track many tasks and calculate future dates for various features throught the application. -a lead calculator for users to enter a few variables and receive required number leads they have to generate (I have formulas for this too.) -e-mail system, chat if it's easy, -many forms, most with few fields and some with financial information. -back-end interface with government web site (I have specs for this) -user reporting structure to match lender employee/manager reporting structure (multiple employies-Manager-Manager-Region) -condition setting and tracking -audit trail of all user actions on web application. i.e.: user "X" logon "timestamp", "ip address". and user "X" change field "B" from "X" to "Y" "timestamp". Please see the attachments for more detail and a hypothetical screenshot mockup.