Mortgage Calculators as Wordpress Plugin

Aim: Provide branded widget for Wordpress
Deadline: 31 July 2013
Deliverable: Files packaged as Plugin for Wordpress

I need 2 calculators that will be offered as a branded plugin for Wordpress that provides a widget that can be added to any widget area.

I have the actual calculation formulas and they are added below as a XLS spreadsheet. See http://www.douglasandgordon.com/services/mortgages/ as an idea of what we are looking for.

The plugin should use tabs (or similar) to switch between the three types and use Wordpress' inbuilt jQuery to provide instant feedback.

Needs to have the following;
Responsive/Adaptive - should work in a variety of widths
CSS optional - admin should allow the CSS to be enabled/disabled to allow custom CSS to be applied if required by user.
Must show branding with link below each tab (bottom of widget)

There will be a 3rd calculator to be added as a separate job (probably @£100) in the near future.

I am a freelance Digital Strategist working for a number of creative, publishing and PR agencies.