Why do you want to replace your radiator? Is your car overheating? Is your radiator busted? Do you want to just spend some money?
If you do want something "better" than just get a 3-core Fluidyne aluminum radiator from Summit or Holcomb Motorsports, but it'll cost you-- around $350 - $400. Otherwise (unless your car really needs it), getting another brass radiator isn't worth the money (IMO).