So in any case, kerosene or propane back-up heat, I should expect to add the expense of a battery powered CO detector, correct?

I'm kind of leaning toward Kerosene now since I'll have to use 1# tanks if I have a propane heater It also seems like it would be easier and safer to stockpile/replenish kerosene than propane for any extended outages. But on the other hand, the propane heaters have the built in safety features. I'm torn.