How can I add specialist wizard bonuses to an item or character with Nearinfinity?

So I'm creating a custom character with a wide array of abilities, but defined in-game as a cleric thief. I would like to add to this character the bonus specialist wizards (specifically, necromancers) have against their school of magic, and the saving throw penalty for enemies targeted by their spells.

I kinda know my way around Nearinfinity, but I'm not sure how to do that or if it's even possible. I don't know how to even access the specialist kits to get a hint as to how to do this.

Anyone can give me some pointers? Thanks