Stephen Sakai, who was convicted of shooting four Chelsea clubgoers, killing one, was sentenced to 90 years to life yesterday. Sakai had claimed he shot the clubgoers in self-defense, but Manhattan Assistant D.A> Joan Illuzzi Orbon told the judge that Sakai (who was already found guilty of two Brooklyn murders and sentenced to 50 years to life) "needs to be in prison for the rest of his life so society can be safe from one more random sicko." One of his victims, Julian Quadros, who is now paralyzed from the shooting outside Opus 22 where Sakai worked and whose brother Gustavo was killed in the shooting, said, "He's a coward ... What he did to my brother - you have to be a coward to not be able to face somebody, to shoot somebody in the back of the head for no reason." Sakai's lawyer said she would appeal the verdict.