The mystery cultist glorious aura is all about Cha, you're looking at a class that keys off that. Sorcerer, oracle, paladin, swashbuckler, seducer witch, summoner - those last two have too much which scales with character level, forget them. So yeah, if you're after a 9th level spellcaster it's sorc or oracle.
Honestly, it depends on which one you want to worship... which boons you are after... which weapon you want to use. Although, being that you said you were looking for 9th level casters, you may not care about weapons too much.
Regardless, Oracle immediately comes to mind... 3/4 BAB, spontaneous caster...
8 levels of Oracle gets you +6 BAB, +2/+2/+6 base saves, 3 Revelations, 4th level spells... good as start as any.