When you say you're looking for a melee class that can stand up to a caster, how attached are you to the idea of having almost no casting ability (as opposed to a melee class with a few spells that can't be used directly to actually win), and how attached are you to the idea of not having to use magic items to do his job?

Also, I would highly advise against making him a purely melee class. He should have at least enough ranged ability (likely from a bow) to ready to disrupt. (He should also, of course, get the ability to bypass standard caster anti-archer defenses.) Something to allow him to disrupt without having to ready every round would be even better.