A dozen 50mm2 aluminum cables sounds a bit weird to me - why not use larger wires?
Unless this is some kind of distribution to several boxes one large feeder would make more sense - anything up to 300mm2 copper goes, though above 240mm2 paralleling is preferred by most sparkies here.
If the fuses aren't supposed to be operated by customers I'd advise HRC fuses for financial reasons. Otherwise breakers are a must have.
I second the need of some kind of metering, either prepaid or cash/ bank/credit card.
In Vienna there's one (I think) charging station for electric cars which is built into a nice red and grey round pillar - a design object rather than the typical distribution box pillar (we've got plenty of them, power distribution, telephone, cable TV, tramway switchgear and signalling,...).
