What you need is a hdmi splitter like this one:-
http://cgi.ebay.co.uk/2-OUTPUT-Pair-...QQcmdZViewItem
I purchased one recently to ouput my HD to my TV and Projector you will probably have to use a mains adaptor with it but it should allow cable lengths of about 15 metres, so placement is the key and some drilling through ceilings and floors.