Aran Ring

a) do that (I'd be fine with this, level 70 is not even hard)

b) figure out how to make a quest give stat improvements to items, and just have a single ring that is "upgraded" by changing its stats instead of exchanging it, resulting in a single item id. They already have NPCs that give out non-average equip stats, should be possible to do this.

Or Lilin could give you a statless ring as soon as you hit level 10 and give you 100% scrolls that each add 1+ all at levels 30, 50 and 70.