You mention in your build weakness that you need to still all your spells and can't use wails untill late. The following spells can be cast fully armored without failure.
Light Flare True Strike Balagarns Iron Horn Blindness and Deafness Darkness Knock Displacement Polymorph Self Power Word Stun Greater Sanctuary Mass Charm Mordenkainens Disjunction Power Word Kill Time Stop Wail of the Banshee
Bcause Scimmy is easier to get than rapier while still being both a med weapon and a superior crit range. Being A STR build you don't need a Rapier, and the fact that around level 38 you lose your large size and revert to a med sized critter you need a med weapon. Plus I have a level 29 Rare Scimmy.
Here is lev 40 Pre Immo, so still not rocking any really good gear, Just a few Rares, No Dach stuff or anything yet, still got along way to go on AC, Spell DC is sitting at 40 Right now. Still got a long way to go on that, AB is actually 2 higher than shown on the CS, and Still got a long way to go on that as well.
I think I've found a layout I like for this. It involves using the ESF Necro book instead of getting the spell focus feats, which makes it weirder to level up, but gives you enough room to fit in saving throw feats. This is especially important because of the new LL save feats. (As far as other changes, I'm also considering starting with 16 strength 16 con at character creation, out of the principle of efficient ability point allocation.)
I would start with Luck of Heroes, and end up taking Iron Will, Lightning Reflexes and Legendary Luck. Even with an end stat of 14 con as you have currently, I think you would have saves of 58 58 58.
In the end, I won't have Empower or Epic Weapon Focus, but I will have good saving throws. (Of course I keep wanting to force the reflex up to 63 because of the hells' DC 65 saves, because it's fun to try, but I'm pretty sure I should just leave it alone already.) I would think your 9th level slots are usually better used for Wail anyways, except in boss fights, where it won't hurt you to tank some of the time anyways.
I'll use my Pale Master bonus feats for Auto Still 1-3 and Epic Spell Pen, which delays my ability to cast high level spells in full plate (outside of Wail which you can do anyways apparently) until level 35, but since that's when I start actually caring about doing real runs I think I'll be fine with going through transitional weirdness doing laps in Rhaz or wherever.
This build kind of wants a few more feats pretty bad. I'd like to think there was a way to make the saves even better, but as it is you're hitting any DC 60 saves the optimal 95% of the time with this. You haven't maxed out your attack bonus, but end up really close. I'm thinking I'll stick with 16 strength 16 con for starting stats, but I'm mulling over the attack bonus (and DC for that matter I guess). I suppose more number crunching will help, but it kind of seems like if the build is worth playing in the first place 1 point of DC won't make or break it, whereas the con boost is probably the safe/optimal way to go. I'm just not sure about that yet though, since the attack bonus and DC kind of completely define the build's performance. I'll think about it.
Here's my build layout. I have this character at level 40 immo now.
"Stinger" (secret UltraRare subrace) - requires Human (changes Appearance) STR +4, DEX +2, CON +2, WIS -2, CHA -2, free feat: Spring Attack, increased base movement rate - fast, able to walk on quicksand, increases character size to large
16 8 16 8 16 int 8
1: Toughness, Luck of Heroes 3: Blind-Fight Ftr B - Wpn Foc (Scim) Wiz B - Spell Pen 6: Still Spell 9: Iron Will Wiz B - Greater Spell Pen 12: Wpn Foc (Quarterstaff) 15: Imp Crit (Scim) Wiz B - Extend Spell 18: Lightning Reflexes
=Epic (7) Armor Skin Epic Reflexes Great Str 1-5
=Epic PM Bonus Feats (4) Auto Still 1-3 [levels 29, 32, 35] Epic Spell Pen