Well, Bracers of Armor would work. And if you use the Arms and Equipment Guide rules, they could be made Wild.
However, AC 62 ... *yawn* ... sorry, but, that's not unhittable. Heck, I've made characters (granted, with 3.0 rules) with AC's in the triple digits.
Here, lemme show you: Insectile (+2) Halfling Fighter (8)/Duellist(10) ... ECL 20.
Base attributes: Str 10, Dex 16, Con 10, Int 16, Wis 10, Cha 10 ... 28-point buy (not altogether uncommon).
Modifiers: -2 str and +2 dex from Halfling; +4 Dex and +2 Wis from insectile; +4 int from level advancement; +6 enhancement to dexterity, +6 enhancement to intelligence,
Modified Attributes: Str 8(-1), Dex 28(+9), Con 10(+0), Int 26(+8), Wis 12(+1), Cha 10(+0)
Now, for feats:
Cha 1 Dodge
Ftr 1 Combat Expertise
Ftr 2 Multiweapon Fighting
Cha 3 Mobility
Ftr 4 ...
Cha 6 ...
Ftr 6 ...
Ftr 8 ...
Cha 9 ...
Cha12 ...
Cha15 ...
Cha18 ...
Next, critical elements of his gear -- granted, the total to purchase this is about 150K over budget fora 20th level character ... but, bear with me for a moment:
Ring of Protection (+5); 50,000gp
Amulet of Natural Armor (+5); 50,000gp
Skin of the Hero (from PsiHB); 90,000gp
Heavy Shield (+5, Animated); 49,170gp
Shield Spikes (+5, Defender); 72,320gp
Gloves of Dexterity (+6); 36,000gp
five Daggers (+5, defender); 72,302gp each
Rapier (+5, defender); 72,320gp
Bracers of Armor (+10); 100,000gp
His armor class, while fighting defensively, using Combat Expertise, and sucking all six (!!) defending weapons AND the defending shield spikes dry:
Base: 10
Dex: +9
Int: +8
Armor: +10
Shield: +7
Defenders: +30
Dodge: +1
Duellist: +10
Expertise: +5
Action: +2
Luck: +3
Natural: +5
Deflection: +5
-----------------
TOTAL: 105
Worst case, drop the Amulet and Skin of the Hero, and the AC drops by 8 (to 97), but the price of the gear should come out much closer to on-target (dropping those two chops 140K off the total). The ring could also go, for another -5 AC (to 92), saving 50,000gp more.
...
And if you allow the Anthropomorphic Animals form SavS, it gets worse. Insectile Anthropomorphic Squid Duellists ... *shudder* ...!