Add 'website' switcher to Magento Store that's using GeoIP redirects

We require a 'Website Switcher' adding to our Magento Multi-store setup. We currently have 3 'websites' setup in Magento, NOT stores.

We currently have a php script redirecting to the 3 stores using MaxMind GeoIP lookups.

We require the switcher implementing within the current website header, taking into account the sites responsive design and not breaking any layouts.

The switcher should allow visitors to override the redirection script and remember the uses choice.

The switcher should show 3 flags alongside 3 currency symbols and work similar to the one displayed in the header of asos.com

Please understand requirements carefully before submitting proposals. Current Magento setup described below.

3 domains

domain.com
domain.co.uk
domain.eu


Website 1 - Base Currency GBP

website 1 > Store A > Store View A


Website 2 - Base Currency EUR

website 2 > Store B > Store View B


Website 3 - Base Currency USD

website 3 > Store C > Store View C