You have a material that greatly enhances electric and magnetic sources or electro-magnetism in general.
In this world, the material, is known to be a naturally occurring liquid found in geological formations beneath the Earth's surface. It would be commonly refined into various types of fuels or blended with other liquids to achieve different proprieties and meet a variety of uses.
When this material gets used, which is purely only possible through human interaction, it generates heat, which becomes greater, the longer it is being used.
The ships pictured below, have to be able to transport heavy cargo, stored in containers of the same shape and size.
These ships should be able to levitate above the ground, while being active and, fly at speeds of up to 120km/h at a height of approx. 300 meters.
Choosing either of the pictured designs, what would be the most simple, technically possible, engine/ moving apparatus, to move such a transport, without or minimally affecting its design?
EDIT: The transports have lengths of up to 70 meters and weigh up to 300 tons, comparable to commercial airliners. I could make them possibly 30% lighter though if necessary.
I also want to clarify that a possible theory should be as close as possible to reality but doesn't have to strictly follow every aspect of it. It can also be related to current theories in quantum mechanics.