heating / h.w. heating questions

[Kenneth LaVoie]

Hi
I am obsessed with finding the answer to the question "what is the best and cheapest way to heat..." - I live in Maine, which lends completely different answers to heating questions than just about anywhere else in U.S. In that light, I wanted to put a couple of quesitons out there:

1. There is some debate over whether it's better to use indirect HW heater (like boiiler mate coming off oil HWBB furance) or electric. I have one bldg that has steam boiler, but oil fired hw heater. It went, so I replaced with electric because the upfront cost was so much less. PLUS it "spreads" my risk. I'm no longer dep. JUST on oil. I could conjecture that oil prices are, or will be, more volatile than elec. prices.

2. BUT...I also put a brand new boiler in a building which ALSO had a sep. oil fired HW heater. It went and I opted for twin 40 gall. elec. hw heaters. Some have said I did the wrong thing, shoul;d've used external boiler mate. So this leads me to my NEXT question...

3. THE NEW "heat pump" based electric hw heaters like they have at HD -- would THESE be a better alternative than indirect HW heater? they are supposed to be much more efficient, taking some of their heating abilit from the surrounding air. And they would all be in pretty warm places (either near furance or in apt or common area). Which leads me to final quesiton...

4. We do NOT have natural gas in my area. But someday we will, and it's supposedly cheaper than oil. Would it behoove me to keep that in mind in my decision making ... i.e. think twice before using electric hw heat because we won't be able to take advantage of ng to heat our water when it comes ...

okay, hopefully these questions are clear enough and I've given enough info for some meaningful conjecture! Other facts: 35 units, all in Waterville Maine. Most Heat systems typical HW with boiler mate or elec. for h.w.