When looking for a cypher module, I'd choose one of the final five AES candidates (MARS, RC6, Rijndael, Serpent and Twofish). I'm basing my choice of password manager on that list, with preference to the winner (Rijndael).

I gathered some information here, on seven password managers for Windows, that I might turn into a review. Anyone who knows (or doesn't) about this stuff, feel free to comment.