Paladin advice...buying magic items. 3.5

OK, have played this paladin on and off for about 8 years...started
him in 3.0.

Am gearing up to take him to 20th level ( 14th now). The current
campaign promises to be heavy against undead, but I suspect demons and
devils will be around.

I have about 40,000 GP to spend on magic items. I'm planning on
augmenting my ring of freedom with feather fall ( I got stymied by a
pit a few adventures ago) and my ring of sure grip ( can't be
disarmed) with a +2 protection. I also plan on buying a pearl of power
for some extra juice spell casting....I can use either Bless Weapon or
Prot from Evil or Endure Elements upto 4 times a day...woohoo.

So, that leaves me with about 25700 to spend. What direction should I
go? I can augment my +3 sword with upto +2 in bonuses. At first I
thought Holy, then I thought making it Blessed so I would not have to
use spell slots on that and could use 4 Prot/Evil. I could then add 1
more power. Flaming is nice, but Devils are immune. Shock is nice, and
in character ( Paladin of Heironeous), but Demons are immune. Frost
would be the safe bet...then it hit me, most of them have Resist 10
anyway.

I can always have the Blessed added later, and go for Holy.

But, I'd like opinions on what magic items I might want to add, using
the Core DMG, Book of Exalted Deeds, Complete Divine, Complete
Champion.

Here's what he has now: +3 sword, +3 shield, +1 Mithral plate armor,
Ring of Freedom, Ring of Sure Grip, Amulet of natural Armor +3, Cloak
of Resistance +3, Ring of Prot +2 ( will give it away if I augment the
other ring), Boots of Striding and Springing, Gauntlets of Ogre
Power.

I thought about adding to the armor, making it glamered and maybe
Ghost Touch, or ModerateFortifacation. But it seems we are in many
adventures where armor is not an option, and I'm still not sure about
glamering a paladin's armor. Following the fluff is important to me.

I've thought about playing to the strengths of the paladin....high
saves, and good anti-evil.

So, any thoughts on must have items within my price range, or what I
should augment or what other weaknesses I might have? My guy is good
at critting, so that would be good against outsiders, so maybe Undead
Bane? Or Holy for the all around?

Thanks for any thoughts!