question about k9 mail "family" and how they work with pure Messenger

[wase4711]

I have the "Pure messenger" widget running, and, I am not sure if I need to have "K9 Mail for Pure" AND "K9 Mail" installed as well..

I get 2 notifications of the same email, which is a pain, so I am thinking I should un-install "K9 Mail," and just use the "pure K9 Mail widget".
Will I lose anything by not having the "full" K9 Mail installed in addition to the "pure" version?

thanks!