Game-changing upgrades (for casters)

[Invurnus]

I'm playing my first caster on P1999, and it seems as though itemization is not as important for them as melees. Sure, a big mana pool is nice, and everyone wants survivability, but chasing that extra INT and HP seems more like a luxury than a real upgrade, at least at this stage of the game.

So instead of chasing INT and HP I focused on getting jboots, which is a legitimately huge upgrade for a wizard - a game-changer, really. My question is, what's the next game-changer, if I'm willing to save my cp's? I'm leaning towards a Tolapumj's Robe, as haste is a nice little bonus for finishing off mobs and leveling weapon skills, but beyond that...? Is a Manastone really the next big upgrade?