Rating the casters as melee fighters

[Runestar]

Or go swiftblade. At lv15, I can polymorph into a hydra, make 24 attacks/round via bounding assault, and still fire off a damage spell and a swift action spell. As noted, wraithstrike takes care of the poor attack roll (hydras don't really have good str score). This is just the basic idea, I am sure you peeps can do more to trick this out. 

[Widow]

I am going with bard, assuming you PrC them up.

Bard 3/Battle Dancer 1/Cleric 1/ Dweomerkeeper 1/ Eldirch Master 4/ Sublime Chord 1/ Dweomerkeeper 9

Alternative source spell feat for arcane to divine spell casting. 
Access to the Bard, Cleric, and Sorceror list. 
Access to Divine Metamagic and reduced metamagic costs.
4 Spells per day that are supernatural, so lets assume you persistent extend each of them for 48 hours of coverage to end up with 8 untouchable spells.
With the right spells you get +44 to Charisma (different types and all stackable if good and taking the Ability Enhancer Feat from the Dragon Compendium)
Cha to AC twice, once as a monk with battle dancer, once from Nixie's or Sirine's grace spell (which ever is the the level 4 one) as deflection
Divine Power and Thunderlance for lots of attack and damage off of Cha
You can abuse wish if allowed, go with persistent Shapechange if you like, or Miracle up a Persistent Swift Haste from the Ranger list, whatever.