well, dont go all american and sue me if im not
i looked at all the above combinations for various reason and all would fit. most king cabs are actually longer than both the normal pick up and the double cabs, this gives the extra room.
i ended up with a defender hi-cap, which i think you could park a bus in!!
i do know someone who has a hinged (fom the side) ivor willams canopy on a new nissan king cab (looks like the old version but i new, called a d300 or something) he parks his quad (old honda 500 hydro) in and then hinges the canopy back over, all fots very snuga nd you woul