Knowledge is Power, and I need more of both

[SpicyBoi_Nezu]

I need a way to gain a bonus to all of my knowledge checks for Knowledge devotion

I already have Collector of Stories, but my DM claims that there is no magic items that can boost the Knowledge skill.

I have to rule out any other feats, multi-classing, and prestige classes, because I have finely tuned his plan for the next 6 levels.

[Scrollreader]

Your DM is incorrect. Check the Magic Item Compendium for the Scrolls of Uncertain Provenance, at the very least.

[Saintheart]

Lore of the Gods, Cleric 2 spell. Grants a passive +5 to all Knowledge checks 10 min/level, or a meaty +10 if your god has Knowledge as one of his domains, which he damn well should if you're taking Knowledge Devotion. Interfaces very neatly and nicely with Knowledge Devotion because while the spell grants an insight bonus to your Knowledge check, Knowledge Devotion adds insight bonuses to your attack and damage rolls, i.e. there's no overlap. Also locks in neatly with Collector of Stories because CoS provides competence bonuses, i.e. they all stack. Lore of the Gods + Collector of Stories means your Knowledge roll is at least a +15 and therefore at least a +1 to attack and damage from Knowledge Devotion.

Divine Insight grants an insight bonus of 5 +caster level, but only on a single Knowledge check. Not great for Knowledge Devotion where your first action in combat should be to perform a scan and roll for all your Knowledge skills and thereby ping the DM's monster in some way.

Guidance of the Avatar is its big brother which provides a +20 to a single check.

[Thurbane]

Very well written guide: The Library of Knowledge: Getting the Most out of Your Studies (http://www.giantitp.com/forums/showthread.php?514547)

[RifleAvenger]

Your DM is incorrect. Check the Magic Item Compendium for the Scrolls of Uncertain Provenance, at the very least.I mean, you're not wrong, but... it's possible you're wrong. If the GM says there's no magic items that increase Knowledge skill rolls, and they're doing it for perceived balance reasons rather than ignorance of a splatbook, then at that table there's no magic items that increase Knowledge skill rolls.

The OP's first step, if not already taken, should probably be to find out what sorts of boosts the GM will accept, if any.