Bilenky has a package deal with the backpack case -- case, tube covers, couplers, and wrench for $340, if you need all of those. You might want to add the compression struts (they're useful with the hard case, not so sure about the soft case). You really want the tube covers to prevent scratching the frame, and the couplers make it possible to assemble and ride without adjusting the cables. Unfortunately it's one of those horrible flash sites, so I can't post a link. You have to go to bilenky.com, click on store, click on travel accessories, click on backpack case travel pack down on the bottom.

If you get the case from Niagara or go with a box, either get the tube covers or lots of appropriately sized foam pipe insulation. Murphy (of law fame) works hard to scratch up the tubes while they're being shipped.