While large, the 747 isn't very effective with the standard cans up in the front 20 or so feet of the nose. With the stairs up to the upper deck there is a large area of space restricted to palletized cargo or smaller cans.

A 777 might actually be a more effective option for you guys. My understading is that the aircraft often run out of volume before they run out of weight (I could be very, very wrong here). A 777 would be longer, and without the steps you'd have cargo space for the full length and width aft of the crew area and the "lounge" behind the cockpit that the widebodies have.