"Simple uber Defense" is Shiver + Favored of the Martyr which grants immunity to all damage unless it's both Good & Chaotic, or no real monster will hurt you and certainly 99.9% of blast spells ignored. Pick up Friendly Fire to
reflect ranged attacks (both spell and mundane) and who needs AC?
From there
+5 Robe of the Vagabond of Resistance (CC/MiC, 26k): +5 resistance and +1 luck to saves.
+6 Empyreal Bracers of Armor (BoED, 64k): +6 sacred to saves, see A&E page 130 for rules on exchanging bonus types.
+5 Parry Spellstrike Gauntlet (SRD/MiC, 72k): +5 to saves vs spells and su/sp abilities & +1 insight to all saves.
Ioun Stone[Pale Green Prism](Core, 30k): +1 competence to saves.
Admiral's Bicorne (SW): +2 moral to saves, all nearby allies gain this benefit as well.
=16 to saves or +21 to saves vs magical stuff.
Which isn't too bad. Maneuver granting items and high Concentration can help as well.
Did you come close to either?