The only guthook knife arrangement I ever liked was the Outdoor Edge Whitetail. That T-handle makes it a lot safer and easier to use. Otherwise, either get a folder with a second guthook blade or a plain knife and a seperate guthook like this set from Gerber:

Edit: the pic didn't come through. It's a Gerber Gator with a seperate guthook and carrying pouch. Costs about $45.