Let me remember
For upper, costume googles (cheap, 30% extra exp)
mid, anything with ATK+1%
lower, anything with SP stone (+1 sp per mob killed isn't that bad)
garment, Costume archangel wings or rudra grace with aspd+1 (that's the best you can find atm)
physical shadow earring + physical shadow pendant + physical shadow weapon
hard shadow armor + champion shadow shoes = extra hp & sp
second option
weapon, kingbird shadow weapon
armor, ancient shadow armor (pair with kingbird shadow weapon)(total: extra ranged damage)
That kind of shadow gear needs the complete set to be pretty useful (also, all must be +7 or +8), that's why free shadow gear is a pretty good option for most of classes