Tancred's Battlegear

Paladin wearing Tancred's Battlegear full set.

Necromancer wearing Tancred's Battlegear set.

If found early, wearing the Amulet and either the Mask or Boots to get the +78% MF will be one of the highest combined MF available.

Parts of this set can be combined with parts of Sigon's Complete Steel to make what is likely the highest MF you can use at level 20. You only need two pieces for the extraordinary MF, the amulet and likely the Helm, which will allow you to assemble three pieces of Sigon's, likely the gloves, shield, and the essential Boots, which will get 50 MF with three pieces.
With Gull, two Nagelrings, and a four Perfect Topaz armor, you could have up to 384 MF with a Belt still to customize, the rather nice 30 IAS, +1 Skill, and 10 lifesuck from Sigon's, and if you're really crazy, the opportunity to put more Topazes into the Helm and shield. All long before Goldwrap and Ist and the likes.
I don't know why you would want to get that kind of MF at level 20, but I believe that's the highest you could (except wielding two Gulls).