Picked this one up from Canadian Tire. A little more expensive but it will run my big pump for over 6 hours. Thats plenty of time to get the generator going if I need it.
I don't worry about heat loss as I made some panels out of rigid pink styrofoam that I can strap to the tank to keep it warm. A pretty cheap insurance policy.
The nice part about these is the switch is instant so nothing has to restart.
http://www.canadiantire.ca/AST/brows...1%252C800W.jsp