Reserves of Strength breaks caster level, but that is kind of 3rd party ish,
There isn't many ways to break caster level caps, though metamagic can accomplish the same output but through a different method.
Psionics does it much better, with Overchannel and Wild Surge, along with not having...
Binder 1, with Improved Binding could bind Haagenti and get immunity to transformation that way as well. Not as easy to get as you would from an item, but it you would go Anima Mage it would be an option.
Tome of Magic has some feats that effect supernatural abilities that you could use on them. They are like the sudden metamagic abilities and thus are once a day mostly. They are in the feat section dealing with Binders.
To bad all the donations incentives between 25$-222$ have been sold out, it makes a large gap of where you might want to donate more, but not that much more so you choose the lower option.