I believe you are in a climate where you would benefit greatly from a heat pump. From my understanding San Diego has a very mild climate. As long as the outside temperature is 40F or higher, heat pumps are both effective and very economical. Below 30F forget it!
The heat pump is quite effecient and should cut the heating portion of that electric bill by about 50%. Look for a pump with a high SEER. The higher the SEER the more effecient your pump is. 10 should be the minimum, but I would suggest looking for 12 or higher.