I purchased my home 5 years ago with an existing 40 gl gas water heater that's dated 1996. It's time to replace it. Of all the newer types of technology, which would be the most cost effective for me? The water heater is in a small room with the furnace in our finished basement with vented doors. Does anyone have any experience with the new GE or Rheem heat pump water heaters? I thought about tankless but the installation costs are huge. I'm in the northeast (NJ). Thanks in advance.