Sorry, this may make your head spin or you may laugh at my amateur knowledge on the topic. Either way here is a quick update.
I have made progress in terms of having the javascript decrypt a mail message. Mail will contain real transactions in the near future. This gives me a some assurance that encrypting the email will go just as well too. All this is required so that we have a working light-weight wallet. I'll continue to complete the message formats and make good libraries so that we can use it in a re-branded lightweight wallet.
I hope I'm getting closer to just coding this stuff myself and cutting out a lot of the library hell; however, for now using the libraries might be good so we can make faster progress on the web wallet and it will be just as secure and reliable to the end user. Code clarity is very important as without that we can not have productive development on the code. Feel free to give some feedback or code review; this is in a very early stage.
http://stackoverflow.com/questions/26595085/computing-a-ecdh-shared-secret-in-javascript ...