Some good "neck" knives are the A.G. Russell Woodswalker, Hunter Scalpel, and Bird&Trout models. They come with kydex sheaths and the Woodswalker is also available with a really nifty leather pocket sheath. They have other, larger models available with kydex sheaths as well. They also have the Canadian knives, by Russell rather than Grohman, which are really well made and well shaped blades. Check out www.agrussell.com.
Knives in checked luggage is usually not a problem with airport security, just don't try to board with one in your carry-on bag or in your pocket.
Hope that helps.