If you're determined to have a two-handed weapon, here are the main choices for you:
Aubriest's Whisper: Potency +120, MAcc -20.
Ivory Staff: MAcc+10, MCrit Rate +10 (Melds with Int, MAtk and Elemental Potency materias)
Lominsan Staff: MAcc +15, MCrit Rate +15
Go with whatever is cheapest till you can multi-meld an Ivory Staff.
Though, if you're open to one-handed weapons, the
Lominsan Scepter is a decent cheap choice too.
EDIT: The one you saw with only Int and HP for 2 mil was the Astrolabe. It's only that expensive because of the Relic quest. Astrolabe itself is THM-only.