Included with the season 1 DVD compilation of Justice League is some preview animation for a pitch producers Bruce Timm & James Tucker made to Kids' WB! for a slightly retooled version of the series. One that would include Robin and Impulse (subbing for Flash) on the roster. Had this been sold to Kids' WB!, chances are we might not have gotten Teen Titans on Cartoon Network 2 years later.
Yes, there's a female version of Cyborg, if you will, who hadn't appeared in the books. Character models were borrowed from other DCAU series of the period (i.e. Batman Beyond). After seeing this, I'd have to say, WB did the right thing by turning this puppy down.