To my knowledge to have high end Legendary items, you need to kill big boss. Exedus right now is a good one. The peerless boss have some legendary items , but not always. Some said that hunting with a luck suit at around 1200 help, some said that the luck had been broken since day one. I try both and get some good loot. I did hunt RC with 1200 luck to get some greater items and specially Jew, and not to forget the golds.
Monster with high karma like RC ( Roating corpse) did me well last years. Covetous Lvl 3 is a dangerous place but at the right days ( spwam chance) u can get some cool items.