Wrestling gives you a defense on par with a weapon skill.
So does the Eval/Anat combo, but I think it requires you to have a spellbook equipped.
But they aren't BETTER than a -0 mage weapon, if your Magery is the same skill level or higher than Wrestling or Eval/Anat formula - plus the Anatomy or Wrestling is taking up 100-120 skill points.
In al three cases, if you get hit, you WILL fizzle the spell, unless you have the spell Protection active, and that reduces your FC by 2, or to 0, whichever is the lower number.