Just to say, I spoke to Automotech and they said the AS-7530D will stop and can used at any height between min and max (110 and 1000mm). They have mechanical safety latches but these are just a failsafe and you can leave the car at any height for prolonged periods of time.
The ramps either end can independently be locked horizontally and are load bearing so you can alter the length of the platforms to suit.
They don't offer any options for beams to go between the platforms, so that will be a home-made mod.