Dark rings with -6 MDT each on them from konschtat [A]. Merman's earrings -2 each. Twilight torque for -5. These are for all jobs.
War can then use nierenshutz for -3, combining to give you -24% MDT, added to shellra V's -27%, you're capped. War can also use askar feet for the last 2%.
Now for magic def bonus. Lamia mantle +1 for 4, then pretty much just the Iron Ram set and replace hands with medb's gauntlets.