Help with an Anti-Spellcaster based build

[Crukul]

So recently I got an idea in my head, and now I want to try and flesh out the idea, but lack the majority of the knowledge to do so.
Basically I'm looking for feats, items, classes, races, etc., that could come together to make a character who is focused around ruining the day of anyone that enjoys casting spells. And I figured it would be a good idea to come around here and ask for info, since that's worked well for me in the past.

[Gavinfoxx]

So you want a spellcaster who fights other spellcasters, yes?

[Crukul]

So you want a spellcaster who fights other spellcasters, yes?

Yes or no. My character having their own spell-casting ability or lacking it is fine either way.

[Eldan]

You need some kind of magical power source. Psionics, magic, etc. Without it, you don't stand a chance.

[Thrice Dead Cat]

For a spellcaster, a sorcerer with improved counterspell, heighten spell, and either Eyes of the Oracle from Dragon Magic or I want to say Spell Battle from Spell Compendium would work well. Consider using the ACF from Complete Champion to get the inquisition domain's power for more "oomph."

[Nerd-o-rama]

Primary spellcasting makes being a mage-fighter easier, because it makes everything easier. I don't think it's strictly necessary as long as you have a) the magic items necessary to reach spellcasters and block their instant win/escape spells (without requiring an action) and b) a means to prevent your equipment from getting Dispelled or Disjoined.

Basically it's going to get really damn expensive and obscure, but it is possible.

Also, the level of the character and his opponents is a major factor here, thanks to the whole quadratic wizards thing. Even another level 20 Wizard can't really kill a level 20 Wizard who's sufficiently determined not to die.

[Craft (Cheese)]

Play a Cleric with the Inquisition Domain (a level of Church Inquisitor (Complete Divine) gives it to you for free as a bonus domain) to get +4 to Dispelling checks.

Play any race with an SLA, then take Arcane Mastery (Complete Arcane) so you can take 10 on CL checks. You can also qualify for Arcane Mastery with Magical Training, if you so wish.

Divine Defiance (Fiendish Codex 2) lets you counterspell as an immediate action by spending a turn/rebuke attempt.

Trade one of your domains for Divine Magician so you can add Spellcaster's Bane (Complete Mage) to your list: It's a swift action 1 round/level buff that gives a +2 Insight bonus to all of your dispel checks, automatically recognize any spell being cast so long as you have line of sight (and 5 ranks in Spellcraft), and if you have 15 ranks you automatically know the caster level of any spell being cast.

Battlemagic Perception (Heroes of Battle) is a 10 min./level buff lets you automatically know when spells are being cast within 100 feet so long as you have line of effect to the caster, gives a +5 competence bonus to spellcraft checks to identify spells, and lets you identify the spell (even if you can't see it) with a spellcraft check. As a bonus, you can end the buff to counterspell a single spell as a free action. Consider Persisting it.

Soultouched Spellcasting (Magic of Incarnum) gives you a bonus to dispel checks (and checks to beat spell resistance) equal to the amount of Essentia you invest. Note that you don't actually have to take an Incarnum class to use incarnum feats, you just have to have Essentia (which you can get from Incarnum feats, or from being an Azurin).