Originally Posted by thijsseh

A1: Registration A6-EPV and newer have the new J cabin. There is no way of knowing in advance which frame will be used on a certain day. For the return trip (i.e. GIG/DXB), you can see the registration of the outbound aircraft after it has left DXB, but that is obviously too late to make decisions w.r.t booking flights.
A2: According to The EK Source - Emirates Airline Flight Tracker., EK247 has been operated by EPV once and by EQE once in the last month. As the question is 'usually', recent stats suggest an ECx frame to be the most likely.