Are cameras finally ready to roll on Warner Bros.' film about the lasso-twirling Amazon? Producer Joel Silver, the man behind the ''Matrix,'' recently hired former ''Smallville'' writer-producer Philip Levens as screenwriter No. 4 for the project, in development for at least four years. Levens is taking his cues from the '70s TV show, equipping Diana Prince's alter ego with bulletproof bracelets and a boomerang tiara. Sandra Bullock has been considered in recent years, but now producer Leonard Goldberg (''Charlie's Angels'') says that he'll cast an actress ''in her early to mid-20s.'' (Rumor has it ex-Slayer Sarah Michelle Gellar is hot for the part.) Levens expects ''Wonder Woman'' to have a director and star within three months. First, he'll have to see if his script takes flight like WW's invisible jet.