As plunet notes convenient can mean a lot of different things. Personally I'd be looking to maximise the layover time by heading into Amman and doing something with the stopover, but if you arrive at 11pm and depart at 7am that might not be convenient. Only the Amman Airport Hotel is actually adjacent to the airport and it has fairly mixed views. But will be your only option if you want a bed to sleep in overnight that's close by.