One of the problems with LP is that it's a derivative of oil, so that makes its cost tied to the cost of a barrel of oil, and that's not good.
Electricity is normally generated by coal, nuclear, hydro and natural gas. That's what makes the price more stable. These are all things we have in the U.S.
If you can, get natural gas instead of propane. It's price goes up and down, but it isn't nearly as expensive as LP, and no one has to refill you each year.
The other thing to do is talk with people that have all electric service and those with both electric and propane service and see what their bills have been over the past year or so. Also note what kind of appliances they have and who their service provider is.
Electricity has always been a good value, but heating is probably the least efficient use of electricity. Electric base board heating is probably a big energy hog and not very efficient. Forced air electric heat is probably more efficient, but not as efficient as natural gas.
After you've made a good survey, then go with what the data is telling you.
Also, before you buy a house, make certain it is very well insulated. No matter how efficient your energy system is, you'll be throwing money out the window and through the attic if you don't have lots of insulation.
Clair