D&D 3E/3.5 Best 3.5 spellcasting prestige classes

[Book of Vile Derp]

I plan to make quick stats for members of The Mosaic Committee in the eberron campaign setting, so I would like to know what some of the best classes would be for an organization dedicated to studying arcane arts. I want around a dozen members I know I want a lv 20 wizard, a Heirophant, and a monk(for their dedication heavy flavor), but I never played an arcane casting PC so I know little more than those classes for them. I know I want to avoid sorcerer since it is inborn and no studied. So...thoughts?

 

[Remathilis]

Master Specialist, Mage of the Arcane Order and Loremaster all spring to mind.

 

[MDK]

Loremaster/divine oracle perhaps?

 

[RUMBLETiGER]

Incantatrix.

 

[ppaladin123]

Initiate of the Seven-Fold Veil for anyone focused on abjuration magic.

 

[Dozen]

As a base class, let's mention Savants(edit:I'm not sure if you are asking only for PrCs, I'm sorry if I got it wrong). At large, they are abysmal spellcasters, but fantastic scholars and assistants. There is a pretty good overhaul of the class on the Playground, if you find the original too weak or silly for your campaign. This also opens up some interesting possibilities, like a Savant who studies the occult side of the arcane and picks the Warlock's Eldritch Blast and the Hexblade's Curse as class features - I'm not saying it's a powerful combination, but it's possibly the only way any legal organization could gain access to that kind of magic without having to hide it.