Anyone have any ideas for heating and cooling a 668 sq' one bedroom house? This will be new construction in northern CA - 50-60's in the winter and 90-110 in the summer. My husband thinks we should go with a window AC and a gas wall heater. I'd prefer to go with a central heating and a/c unit - pros & cons? Also, the unit and ducting will need to be in the attic as we're in a 100 year flood plain and we'd have to have the house too far off the ground - the ducting would have to be 3' from the ground. Thanks!