Spiked chain fighter/ToB class with Mage Slayer line of feats, Improved Trip & Improved Disarm, Shadow Stride/Shadow Blink, and an item that perma-radiates AMF? Getting large size should help tremendously, too. That way you can screw up nearly everything those casters could hope to do by teleporting beside them and locking them down. Also, perma-AMF means you can't be targetted by divinations, so it'll be much harder for them to anticipate you...
Remember, if they are wielding something you want to disarm, trip first and use the disarm as the free follow-up. +4 to your opposed roll, because you are meleeing a prone foe, and his is -4 because he's meleeing while prone.