Change Master Page based on search results??

hi,
I am using master pages.
On the home page I have a search menu where a visitor can find people in different countries.
for example they Select "Germany" and click go it takes them to
www.MySite.com/Country.aspx?Id=2
On Country.aspx - I want to add local ads for services that are relevant to germany only.
OR
if the search query was Spain - notices in Spain would show instead.
Can I do this by Making a seperate master page for each country and add content to
it unique to that country  - then select
it somehow in code behind depending on what user searches?

thank you