Items to change to a specific animal

[Patsy]

I was reading a George R.R. Martin short story about a witch with a cubboard full of different cloaks, each of which allowed her to take the form of a different animal- a feathered cloak to become a fierce bird, a werewolf's pelt to become a wolf, etc.
I thought the idea was neat, and I thought my players might like something similar added to our game. So is there any existing wondrous item that allows a wildshape-like effect into a specific creature?
If not, what level of character would something like that be appropriate for? I'm feeling a bit lost. Say, something like this:

Grey Alys' Feathered Cloak
Wondrous Item
When activated (a standard action) this allows the wearer to change into an eagle, as the Druid's Wild Shape
Strong Transmutation, CL (?) Price (?)

[Patsy]

Tentative bump.

[Righteous Doggy]

I'd say the wildshape would depend on the animal in question. at 10th level, a wolf transformation isn't going to do nearly as much good. I... have no idea on what the levels would be though.

[Darrin]

Well, in the DMG, there's the Cloak of the Manta Ray and Cloak of the Bat.

There's also the Phylactery of Change in the A&EG, all-day polymorph up to 7HD.

Otherwise... you're probably looking for a custom magic item. And there are some 1st-level transformation spells that would work very well... aspect of the wolf in the Spell Compendium and winged watcher in Complete Scoundrel.