One of the coolest bonuses of Transmogrification is "faking" dual-wielding on classes that cannot dual-wield, by using a main-hand and off-hand that look identical. The trick is finding such elusive options.
Here is one example for mace-using casters that looks pretty cool and is quite easy to obtain.
Giant Club of whatever - random low-level green drop, check the AH
Chopped Off Ancient Limb - Horde quest reward, Azshara
Talon Branch - Alliance quest reward, Felwood
Apple-Bent Bough - Purchased for 950 Justice Points
(Note: I wouldn't be surprised if the ilvl 346 items disappear when 4.3 comes out? So if you want to use this item maybe snag it now.)