There is a national knife show held in Atlanta, Georgia every June (I know that was last month, but if you have no success anywhere else, there's always June, 2008) called the Blade show. It's the largest single cutlery show anywhere in the world. The chances are that you could find a Gil Hibbens Jackal there, but be warned, as with any limited number collector's item, the price of one is almost certainly going to make it something that you would most certainly NOT want to "play with" unless your name is Trump or Rockefeller. Even then, knives aren't toys, so you should be careful with them.
If the Blade Show option doesn't work for you (there's also one on the West Coast later in the year, I believe), you can always try places like EBAY or some or the larger cutlery dealers on the internet. Be patient and you might luck out. Stranger things have happened.