Rigga
Not sure where you are going to put freight downstairs on the Tristar K 1 or KC 1 as the lower holds have additional fuel tanks in them.
Nor do I understand why you think outsize freight can go through the main floor cargo door on the KC 1. All fright has to travel on standard size 108 x 88 inch pallets. There is the capability to link 2 pallets accross the width of the a/c though and thats how the majority of JP233's were moved to theatre during GRANBY - oh that seems a long time ago!