Hi, we are hoping to buy a heater for the pool. The pipework for gas is already there as the previous owners had a heater so we literally need to find a good but not overly expensive pool heater. I am after recommendations. I see Raypak is a good brand but don't understand what we need or why one heater is better than another or more expensive. We really don't want to go much over $1000. Is this even realistic? There seems to be a lot out there but I don't know where to start. thank you for any help you can offer