Armor /QuestsFollow

You absolutely won't do any better than getting defiant armor, through random drops, or bought in the bazaar. This will cover all of the main armor/range/weapon/shield/charm slots. Then there are three more pieces you can get for shoulders/waist/back from the daily Franklin Teek quests in PoK (near Guild Lobby entrance). Finally, the 6 "jewelry" slots (rings/earrings/face/neck) can be bought from a vendor in PoK, towards the east end of the zone, not too far from the big bank (head SE from big bank, go through archway to outer area, and down the small bridge, should be right there, near a tree.

Tat

Everywhere from level appropriate mobs. Like the 59-70 armor doesn't start dropping til 65+ mobs normally, and rarely off of 60-64 mobs, maybe slightly lower.

I second defiant, 'cept for weapons for melee / hybrid. You can usually find twink stuff in the bazaar that is better ratio (damage divided by delay, or for Rog, backstab damage in primary piercer) for cheap.

That being said, the post at https://everquest.allakhazam.com/forum.html?forum=1&mid=1257098999157712273&page=1&howmany=50#msg1257117320232309003 may help some. There are also some good (better ratio than defiant) weapon quests in Blightfire Moors. See https://everquest.allakhazam.com/db/qsearch.html?zone=432

Defiant is so good, that a full set of the Tutorial gear is more than good enough until the 50s, along with whatever defiant drops you get while leveling. Another source for defiant,m besides drop and Franklin Teek's hotzone quests, and the defiant jewelry merchants in PoK in front of the Crescent Reach stone, is following the Hero's Journey achievements (/ach in-game command). See https://everquest.allakhazam.com/db/quest.html?quest=5553

Alternative for wrists and jewelry, is to go with various Trio setting jewelry and augs. You could go with Platinum Trio stuff by your level, along with various cut Underfoot Diamonds or Taaffeites which will be the most expensive part, along with Round Cut Opal (HPs) along with Peridot (AC) or Emerald (Mana/Endurance). This will easily max out your stats (why you use different cuts of Underfoot Diamonds and/or Taaffeites), and 10 or 14 with Peridot AC, 10 to several stats and resists, and 160 HPs, and 100/160 Endurance depending on Peridot or Emerald.

Yther Ore.

Lately the bazaar prices on low lvl defiant gear has been kind of high. I have some alts still using some of the tutorial gear in the 50's. I would do the hotzone quests every chance you get. Also you can do multiple levels at a time if you so desire depending on your level. Say if your lvl 35 you can get the lvl 20, 25, 30, and 35 and do all 4 of them. Just make sure you get them all at once.

I'd also point out that as a rogue, your armor isn't going to be that important anyway. Not enough to spend tons of time trying to keep it up to date. Get a good damage/BS primary hand piercer, and good ratio offhand weapon and spend your cash on a tank merc. That should easily get you up to your 50-60s quickly. Then think about gear. Your levels will go by so fast up to then that you wont be able to keep your gear up to date anyway.