Did some quick mockups for end credit ideas - please keep in mind that they are pretty rough, not exactly what i was going for in style, but similar. Just didn't have the exact sources on hand that i wanted.

And while on the subject of credits / titles - had you considered at all moving the quote you wanted to use to the START of the film and the WATCHMEN title to the END?

The quote might well make for a good story opener and only showing the title at the end of the film is something that has been done, it just doesn't seem to be very common. iirc a [somewhat] recent film to do this was The dark Knight, for example.

* My initial idea was to create faded / worn images of the characters - sort of like shown here...

http://fontfeed.com/archives/tip-the-wornweatheredstamped-look/

high contrast Black and white and then tinted [watchmen] yellow. I would keep the actual text crisp and clean tho, only 'weathering' the characters.

EDIT: I just found some decent quality source images so I may try again a little later...

http://www.impawards.com/2009/watchmen_ver10.html