I have the opourturnity to buy a five ton Heil heat pump. I have a 3000 sq foot home. Is this to big? What work will I have to get done to swap it over from a outside air condition unit indoor electric heat. My electric bills have been running over 500 a month. My electric company checked things out and said a heat pump would help a lot. I know nothing about this at all. Could someone fill me in on pros and cons before I jump into this.