Select Country - site changes on selection (wordpress)

Hi We currently have a website which uses WordPress, the website lists all our other sites we own however they are for certain countries. For example Website A might be for the UK only and website B might be for the UK and US. They want to be able to select their country and then the other sites that are not for their country are greyed out (but still clickable). You can see our website here: [login to view URL]%wme%[login to view URL] (remove the percentages). The 'Select Your Country' link (which wants to be like a drop down box or AJAX kind of thing maybe wants to be on the right hand side corner of the box where our websites are listed. Let me know if you have any questions. Thanks a lot.