Empress gear is your cheapest option for a decent end game play.
Full EMP Gear
Evo 1-3 + Dark Angelic Blessing are your cheapest decent option for rings
Earrings would be anything with %Stat (6% is usually the minimum before upgrading to an even higher one depending on funds)
Other Cheap, but okay Accessories could be Rising Sun Set.
There are no quests you can do for best equips. Maplestory was never like that. Unless you consider bossing 'questing' since there is pre-reqs.
If you're really poor. Simply going for this is a good way to go until you get more money:
4 of EMP equips (Overall, Hat, Glove, Shoes)
Rising Sun Set (Face, Earring, Ring, Belt, Pendant)
Silent Crusade Ring (Chaos it and hope for the best), Tempest Ring, Silent Crusade 1% Exp Ring
Kenta's Goggles
3%+ Cape
Buy best secondary weapon from NPC
I dont think I left anything out. Your best Medal will be Silent Crusade Champion when you complete first 2 chapters.