I generally farm Shadowguard for legendary artifacts and the drops because I can get about 15-20 legendaries & ~1-1.5m gold an hour. But if you're just starting back, thinking back to when we started, I farmed Greater Dragons in Fel destard for jewels using a tamer in full luck gear for the extra drop chance. Sadly, the gear is still like it always has been, random as hell, so you could get the best stuff ever off a mongbat. Someone like Bealank(sadly I lack the knowledge of how to link a person so they see the message) may be able to give you a better idea of where to farm for high end jewels and things. I've got a couple bags full of legendaries in the fel castle that I could allow you to peruse if you'd like (it's only in fel so we can have a red and farm up our justice to cap for spawning/harrower). My house is a complete and total mess, I've never been one to decorate or organize terribly well, but I'm happy to let you take a look if you want. We also have a variety of ssi/stam increase jewelry that you can take a look at as well. We have literally 6 million iron ingots and 60k+ of all the colours aside from Valorite being at like 45k right now due to a lack of interest in mining lately. I haven't had ICQ since 2004, but I could probably acquire it again... I typically use Steam - Goochbeard (Greg Roberts) if you wanna add me(this goes for anyone on legends).
I'm a Journeyman Electrician/Plumber, nothing like car sales, I'd argue my job is easier than yours actually... So I completely feel for you on the long days, I am VERY happy to be out of sales and back to my licensed jobs I love and actually enjoy. Feel free to drop me a message on Stratics as well, it's generally just one of the many tabs I leave open and check regularly for alerts/messages. I'm around pretty much every Sunday (Good old Texas being Bible country

) and I'm off the occasional Saturday like today. Just drop me a message, I'll add you to the house friends list and I'll just unlock the legendary bags and the ones with ssi jewels so you can browse em, any crafting materials you may need, just ask. Like I said, we have a boat load or 20.....
Ah, and I could probably piece together a pretty decent set if you need one, I have LOADS of extra pieces from crafting the 2 sets we are currently in, only thing I'm lacking atm is Essence of Order for LMC imbues. I will say, we make most of our weapons using normal quality weapons bought from vendors so we can just reforge it to 100% ele and not have to bother whetstoning DI off because we utilize sets that have 100% DI base and normal quality 2h weapons still have room/weight for a full 5 imbues. I believe I could make a set with 70% though... I am lacking an extra pair of Tinker Legs, and an Extra Jumu's Sacred Hide from Shadowguard to get it to 100%.
I do feel bad always calling out Bealank as a knowledgable player, but she's one of the few people I know plays on Legends, and I know she's damn good at the game.