It would be hard to say what one should use as gear because each spec and play style and stat for each person even artifacts are all different. All I can say in terms of gear is go for crit until 100% then power but dont forget to get the armor pen to 85%. However you wish to obtain the stats is really up to you. I am sure someone else may reply with a better go after this gear suggestion but I my self main a warlock as my main and read many many guilds with suggestions on gear and what I found was for me its best to go with what stats you need.
Companions mostly do a lot of the work. Actually SW has 2 popular builds. If done right, your "soul puppet" will generate much more threat and it gets all the attention. I also keep a man-at-arms companion on mine that generates threat from crushing strike as well from items. Soulbinders and soul puppet builds work hand in hand also includes 2 Immolation Spirits as a daily. Hellbringers are popular with the Pillar of Power (green ring on the ground) and Gates of Hell abilities. You can still use the soul puppet but not as effective with the SB paragon path. When you chose the Damnation final ability, the Soul Puppet becomes a permanent feature, like a second companion until it is defeated. It will spawn again when you kill something.
I really don't believe gear has much to do with success, other than knowing to choose Lifesteal as your primary consideration. Recently I am using the artifact the generates a stone of Belial's Portal Stone as my main item. All other items focus on stats of Power and Critical Strike. You won't need much defense when the enemy is far too busy dealing with their fear of your minions.
Demon Lord's Immortality set. Hands Down. Period. I have tested many different options including black ice belt and cloak. All are inferior including the new barovian sets if you are gearing for dealing damage. Many ppl will surely disagree, however, do the math. Numbers don't lie or mislead, unless you are looking at success chances reguarding upgrades. ;P
Answers