Legally, a trailer over 750kgs gross weight needs auto-reversing overrun brakes. It is not feasable to make car drum brakes auto-reverse and even in normal use car drums do not meet trailer brake efficiency levels anyway. Plenty of people just do it anyway, its simple enough to hook up the handbrake cables to an overrun hitch and the chances are you will get away with it. Until the day a bored VOSA inspector pulls you into a checkpoint......
Plate it at under 750kgs and forget the brakes. Legally the most simple way, but the empty weight of the shell will probably not leave much room for a payload.
Aesthetically, these things usually look good from the rear and gash from the front. How you close off the hole in the front is what makes or breaks the styling. A flat sheet of steel usually looks gash - try and find or make something more aerodynamic and that looks a bit better. One of the better ones I have seen (non landrover) used a couple of scrap bonnets to make a slightly triangular front to it, but he had lined up the swage lines of the bonnets to match those on the rest of the shell so it looked pretty good.