Great question! In addition to the super answer that you already received from Eileen (I took a couple of notes myself) here is a calculator that Peace of Mind Home Inspections passed on to me. It is found at Buildinggreen.com and the direct link is buildinggreen.com/cak/fuel_cost.cfm
I used it to compare costs of several different fuels and aplications.
Hope that helps
1. A hybrid system is probably the best answer for you. I am making the assumption that you are talking about putting in a new heating system and can make the choice. With a hybrid you use a highly efficient heat pump and add a gas backup for the times when outside temperature is too low to make the best of the heat pump. (choices in the features of the system will depend on the amount of money you have to spend up front) Ask about multi phase, variable speed, SEER ratings. It goes on and on!!
2. If you really have a bundle of cash to spend up front I would suggest you look into a geo-thermal system.
3. If going green is your goal be sure to check out some sort of solar system to see if you would benefit from adding that. (research the stimulus package to see if there is something in it for you if you go solar)
4. For pure comfort, what about an in-floor system. (not just "warm tiles')
As you can see you have a lot of reading to do, or you need to consult with an expert in the field.
If you are asking whether you should buy an older home with one system over the other, that is another question and we can give you some guidance on that too.
Eileen's Green Team
NOTE: If you want to take a short cut to the bottom line you might just go to
http://www.ecobroker.com/ Is a great place to start. Go down the left side of the page and click on "links and resources", or copy the line below into your browser:
http://www.ashrae.org/technology/page/938 is one of the links on the resource page of EcoBroker It has lots of highly technical stuff that the HVAC guys use.
Be sure to visit the US Department of Energy (DOE) and EPA links.
Learn about Energy Star (SEE BELOW)
If you drill down far enough you will come to this page:
This last page is probably the one you want to GO TO FIRST if you want to read about a wide range of ways that you can save energy without necessarily installing a new HVAC system.
Hope this helps. Be warned; it will take you most of the rest of your lifetime to search through all this material if you follow all the bunny trails that you could follow just starting with the EcoBroker site.
:) Have fun!
Eileen's Green Team