Boosting spell penetration

[Max Caysey]

Hello friends... I am looking for ways of boosting spell penetration.

So far I have:

Feats: spell penetration, greater spell penetration and Epic spell penetration

Spells: Assay spell resistans, spell vulnerability, and True Casting.

What else is there?

EDIT: Sorry for all the typos, I was on my phone.

[Extra Anchovies]

Arcane Mastery doesn't boost spell penetration, but it lets you take 10 on checks to overcome SR. Lets you be a lot more precise when figuring out if it's worth trying to cast through SR or not.

There's also probably some items somewhere. Anything that boosts CL, really.