Dodgeman is correct. Electric heat is as close to 100% effecient as you can get. As far as cost effective that has to do with what your electric utility company is charging for power. My understanding is that the northwest can be very competitive with other energy sources.
There is another manufacturer that you may want to consider. King Electrical out of Seattle is a good company with an excellant furnace line. There web site is - http://www.king-electric.com/.