The CV is the Command vertical shaft. The CH is the Command horizontal shaft engine. Never heard of the KH. It isn't shown anywhere on their site that i can find either-
I think way too much of a deal is made over scalping with 72" decks, but it seems to me that you have already answered your own question if your storage building door is too narrow for the 72" deck to fit through. You can cut that much land on a 61" machine plenty fast enough, especially if you're a HO.