Ike at Pangolin 4x4. His site lists some 109's coming up for sale soon. They pop up on Craigslist too. You might also try calling some of the company's that manufacture parts for them or work on them - they may know if one for sale by word of mouth - not advertised in the regular places.
And then of course there is this one. Perfect for a family - but pricey I am sure.
http://www.coopertechnica.com/1961-Land-Rover-109-Series-IIa-Station-Wagon.php
And then of course there is this one. Perfect for a family - but pricey I am sure.
http://www.coopertechnica.com/1961-Land-Rover-109-Series-IIa-Station-Wagon.php