If you're building it (or buying it for that matter), making the tank 3' wide and 2' tall would be significantly better than making it 2' wide and 3' tall.
As you'd see from a search, rays have been housed with fronts but you're talking about a hardwater fish from Africa that would prefer a pH around 8 in a tank with a softwater fish from South America that would prefer a pH of 6. It can be done but the question is: why?
There are zillions of threads in this subforum on sand. Just search.
On the subject of lighting, rays will prefer things dimly lit but since they can't get out of the tank and switch your light off they'll put up with whatever you end up doing.