There are a number of possibilities with Geoff Johns being a top candidate because of his success as a Superman writer, affiliation with Richard Donner and willingness to actually be involved in a Superman movie.
For artistic influence it would be great if they could get Alex Ross and/or Jim Lee to be involved in some way. Ross seems(ed) interested in notion of working with Singer.
Source:
http://www.ugo.com/channels/comics/features/alexross/default_5.asp
Not every successfull comic book movie has taken this approach no but it wouldn't hurt if Singer tried something like this.
Mike Mignola who created Hellboy is heavily involved in the films, Jon Favreau consulted a group of comic book
writers and artists for Iron Man and the same was done on The Dark Knight where Jerry Robinson
consulted.