The clavier, in any variety, is the end-all, be-all instrument... in my opinion. They`re diverse, and they apply musical theory in a very understandable and formulaic way. Certainly, the piano being one of the more diversified instruments known to man, (I believe myself- and have been told by elders) : thus learning first the piano greatly eases and adds to your music career; for things basic to the piano are in many ways integreted in other aspects of the musical spectrum. Therefore, in my personal unproffessional opinion: piano would definately help.
I have fiddled around with an electric organ once, it was a Baldwin, and I can really see the importance of fluently understanding the bass clef. I have only dabbled with the piano, composing a bit- but my chief experience is in performing vocals (only recently have I begun writing for those). But, to ease your pain, try writing. I have found that there is no better way to become familiar with a clef than to dive into it head first.
I hope that helps.