Since the TS asked about reliability, I recommend keeping the separate diode across the relay, and kept as close to the relay as possible. The external diode is more rugged and help will keep back EMF confined to the relay.You don't need the diode across the relay, there's one already built into the ULN2003.
The relay is still showing a part family that I don't think has a 5v version (I could be wrong on that, i didnt do much searching)
The ULN2003A is the 5v version