I agree with Damaged about crediting the lyrics and music separately. I like the way that Dream Theatre do it:

Lyrics: xxx
Music: Dream Theatre

That way, they can give credit where it's due for the lyrical themes of the song, which are often a result of individual or paired efforts, and for the music, which is so often based on the input of the entire band.

In many bands, while the whole band may have some degree of input into writing the music of a song, it is often only the person or people who wrote the largest portion of the music that are acknowledged in print. Correct me if I'm wrong, but this sounds like the kind of thing that you and your co-guitarists had in mind. Your bandmates may be cool with this, or, as Elklander said, they may not be. Either way, it's best to have a candid and thorough discussion with them about the crediting process. Communication is the key to all band issues!