Replacing waste drain metal piece on cast iron tub. Don't know which one to get. The one with the lever, the kind that you manually lift to open? Which type is better? The only ones I could find in stock in brushed nickel are Watts or Pegasus brand. Want to get one that will last. Also, do I need to get the entire assembly, with the drain pipe, if the tub is already in? Told plumber I would have everything here when he comes next week. I'm just wondering how he will get the old one out?