I dont know anything about Hidden Valley, I would call them and ask for a few references, and be sure to call them. That is the best way to find out.
Important questions: How big an area? How many other hunters will be in it?
Will a guide be with me through the hunt? (do you have a rifle, and can they loan you one, will you be able to test fire it first?) What fees are included? (tip, hunt fee plus trophy fee if succsessfull, trophy preparation, butchering?)
Where and when is the knife show you are going to ? are you going as a exhibitor or a visitor? I am asking only because I might want to go to it too.
Thanks, Dave