looking to purchase a heat pump heater, 14,000 gallon inground, either a Pentair or Haywards, pool is saltwater, pump and filter pentair salt system is a haywards, what is the best heater to use, best warrenty, all around best buy? and also compared to using a propane heater instead, we are looking to get more use out of the pool in the month of late May and extending into late Aug early Sept, we live in central Pa, have yet to find someone who can give me good advice on which way to go and which one to buy, Thank You