Depends on how the DM rules timestop, largly. If you can blast things while timstopped (like fire off a chain lighting), the you're basicly SOL.
If, however, timestop only allows buffs and delayed spelld (like delayed blast fireball), then you have a chance...
These are both EQ classes? I'm not very familar with d20 EQ, though I know a good deal about both games.
Mislead, if it's on the enchnter list (it certinaly fits that list), could let you burn off some of his mana by focusing on a doubble. Of course sice it's invisibility it may kill off your animation, depending on the rules for d20 EQ. Also wizards are very dinination focused, so he'll have see invis or true sight up, most likely.
Theft of though (form EQ) would be a good opener, as would mana sive. Get your MR buffs up, just in case, but remember that a wizard has acces to DD of all types...
If D20EQ enchanter DD includes a stun component like in EQ the lowly sanity warp could keep him against the ropes for a while, since you can interupt his spells with it and the cast time is fast (again, if cast time is in D20 EQ, I know weapon speed is...).
Wizards don't have many pets, aside from the sword of Xevim or such, so you won't need to worry about that, at least. Having Rune V up could still be a good idea, but the spell slot you'd want for charm against a Necro or Mage isn't really nessessery.
Best option is to start with a fast stun, like whirl till you hurl then mez him as soon as that ends. Then use theft of though and mana sive a few times for good mesure. Keep an animation up so he'll have to deal with that once he hits you. Dispel / Cancle once the animation starts after him to trash his leatherskin.
Again, without knowing much about d20 EQ I don't know how much of this will work...