Rheem RXCH-A14 drain pan needed
I wish I had a money saving answer for you,I dont.
Maybe replace the whole system and try to get your money back on a higher sale price of the house or at least break even on what replacing the coil is gonna cost. Most AC guys are so busy now they're not doing the small stuff. if your replacing the whole thing you'll get call backs, if you heaters old too try to get him to do that for cheap Im sure his plumber would jump on a heater job.A high SEER ac and 90+ heater should make some money.