well, I have a free idea for a set, if you are interested in it its yours
its a 5 rings sets (Earth, Air, Water, Fire, Void rings) that can give a good bonus when you paired them with a dfferent ring
let's say... if you pair Fire with Air you get a speacial bonus, and Different if you pair Fire with Water (don't know if it can be done)
in a similar way as the classic set items (every item had a set bonus in green when it was paired with other item of the same set)
of course, since the set its impossible to get completed on the character, you should give in the 2 set items bonus the Complete set bonus.
the idea is that every ring had different bonuses like example:
Earth Ring: (earth its the element of the resistance and vitality, it should give high bonus to life and physical resistance but doesn't give attack speed, maybe FHR and should lower your magical resist
)
Earth Represents: Resistance and Will
Physical Damage Reduced
+ Vitality
% FHR
+ AC or %ac per clvl
+% requeriments if you use it in a formule like I was thinking to do in my mod
and maybe poison resistance or damage to Demons
Air: opposite to earth, it should give high bonuses to mana and -req)
Magical Damage Reduced
+Energy
% FBR
+ac against missiles attacks
-% requeriments (so you don¡t need to much requeriments to wear items if you use it in crafting recipes
)
and maybe Lighting resistance and mana leech
Air represents: Reflexes and Conscience
Fire represents Agility and inteligence (wrote correctly? doh!)
Water represents strenght and perception
void represents all the four elements in one, it also can be only spawned if you combine the four rings in the horadric cube
its only a idea, maybe you can find it interesting or maybe not
lol
. Uniqe small charms shouldn't spawn with better mods than 3-7% crushing blow, 3-7% open wounds, +1-5% to max resist and such. One of uniqe grand charms could have only a +1-2 to all skills 
) it could balance the game quite nicely.
, you must use the same itemtype only once per set, else the game will treat 1 ring as all 5 rings.
) to make the Earth ring
Yes, that was it, so your idea would work, and be pretty cool 8)
