Budget program

I am after a budget program for clients to enter their own household budgets into. I want it to be bolted to the back of our website with individuals having their own login and password to be able to enter their budget. I want the budget to have two columns, budgeted and actual with a difference being shown. I also wish to have a calculator built similar to this one: [login to view URL] I want the details of the budget to pre populate the cashflow details page. I will email the details of the budget headings as well as some screen snapshots to the winning bidder so that they can easily understand my requirements. I am unsure of the operating system to use and am open to suggestions. I also want to be able to download the budgets and set up reports with the data. I run Windows Vista with Microsoft 2007. Any questions please email me.