It's really simple.
Go to Webmaster Tools and tell Google which country the site is aimed at. It doesn't matter then if the server is on the moon provided that it's fast enough.
I've got sites on Australian and American servers (.com, biz, .ws, you name it) targetting the UK. They still do OK. For a major site though I make sure the server is in the country it's aimed at - you can't be too careful.