both singer and optima are excelent batteries. some say they are all the same. And i believe optima makes a civic battery. I know my buddy had to do some cutting to fit his in his civic.
You can get an optima batt for ur civic, because i used to have one. Go to ur nearest autozone that carries optima and ull have to order one b/c they dont carry them in stock. I know because I work at one.