Maloney is in the first season of a 3 year $800k deal with the Panthers. He's the current NSW number 6 and is pretty much guaranteed to be either 6 or 7 for Australia this year and next. There ain't a cat in hells chance he's leaving the NRL yet. He does have form for only lasting a couple of years at a club, but he certainly ain't done in the NRL by a long shot.
The biggest name half now available in the NRL is Corey Norman. He's not wanted by the Eels, and there won't be many NRL clubs wanting to take a punt on him due to his off field antics. He'd potentially end up over here, and would be outstanding in Super League.
There are whispers the Panthers need to offload some of their bigger name, older forwards in order to free up funds for their mountain of juniors coming through. Trent Merrin and James Tamou are the ones supposedly available, though I'd expect both to pick up handsome NRL deals elsewhere. Both would be worth throwing the cheque book at though to try and tempt them.