Are you sure they have an airbag?
I ask because I believe the KA seats are basically the same as the Puma seats I have.
I originally thought they had an airbag because of the wires, but on closer inspection it was actually a pulley and tensioner system working on the mount attached to the seat.
If they are air bags, or the tensioners, they should be fine as long as you don't connect the wires. Bit more nerve wracking if they are heated and you are looking for the right wires to connect up. Otherwise just tape the ends and tape them up under the seat out of harms way.
I looked at the belts, the puma ones may be different to the KA, but they had no metal clip to bolt to the car, instead it was a loop stitched in the belt and a horizontal rod fastened to the car. this allows the lower outboard mount to slide back when not in use so it does not trip people getting in and out of the back, but when in use slides forward to the correct position.
If you do use the belts attached to the seats then the seat mounting needs to be strong. the runners on the ones I have seen all have two bolts on that corner, but only one on the other 3 corners.
I would expect though that with a little checking there will be other belts, probably from a four door ford, that could be fitted and would connect with the seat mounted clip.