Don't see how you can lose with an electric tank, provided you have the space for it. New tanks have very low standby loss, no vent required, won't heat the space they're in, are efficient at conversion and are considered a five and dime option by many. Make up air is not an issue in a tight well insulated house.

Propane can be iffy, pricewise. More usage (consumption) equals better pricing, usually, especially if you own the tank. But that carries maintenance and re-cert hassles.

I'm not a fan of oil heated water in the non-heating season.

Thanks, I am not a fan either of oil in the off season. I am considering the electric tank. It is a family of three, my wife and I and our daughter and that is all. We are looking at a 50gal tank.

Have you committed to oil at this point? You said new construction, and eastern Pa. You might want to consider a heat pump, which can be fitted with an exchanger to heat domestic water. Payoff is high in the cooling season.

I have a friend in the Allentown area with H.P., installed as new construction two decades ago...he swears by it. New models appear to have overcome their weakness when temps go below thirty.

Requisite ducting is better accomplished with new construction vs. retrofit. An all season HVAC unit has appeal.

Alphonse, funny you should mention that, my builder just called me wanting to have me talk with the HVAC people and consider a new heat pump. I actually work in Allentown!

The Heating & A/C forum on this site has some knowledgable heat pump posters...there are some MFG.'s that you should avoid. Carrier and American Standard seem to have a good rep.

200A service is common anymore, but be advised that the back-up strips in the unit will require ~100A. May not be an issue if your propane fireplace insert is capable of BTU req'd.

If you do go with the H.P., consider the possibility of having a plenum/return near the fireplace to duct hot air around your house.

If you are still looking for options on water heat, I can tell you I have an oil hot water heater and love it. My neighbors have electric hot water heaters and get electric bills through the roof and poor recovery. With my oil unit, 2 people can be taking a shower at the same time and not lose hot water. 10 minutes later, it's good to go for someone else.

Downsides are: Gotta pay for the oil, but it doesn't use much vs. the furnace. Gotta have the burner cleaned and serviced every year. May need a separate flue -- not sure about your local building codes. I have an Aero unit, have had it for 10 years, and have never had a lick of trouble with it.

Go with Indirect Hot water which runs off a zone of the oil boiler. much cheaper than electric and it gives you pretty much unlimited hot water.

its a storage tank with a hot water coil inside to heat the water. the boiler only runs when you need hot water.