Where is the house located? I am not a fan of hybrid water heaters for my climate in Portland Or, but there are places they work. Do you ever run out of hot water? A pro really needs to take a look at the house. I have a tankless in my house but its usually not very cost effective to have installed PROPERLY with gas lines sized correctly and plumbing done as specified. I think for tankless the Rinnai models are often the best bang for the buck as far as reliability, efficiency and price. There are less expensive models but don't expect them to work as well or last as long. There are more expensive higher efficiency models but don't expect the price to be in line with others.

There are minerals and traces of other chemicals in your water. When the water is heated, they get together with any exposed metal in your tank and form precipitates. These are solid paricles which fall to the bottom of the heater, where the burner is. As they collect, they form a layer across the bottom. This layer becomes thicker over the years. By the time you start to notice hot water shortages, this layer is probably a good five to ten inches thick. The higher you turn the temperature, the faster the precipitate forms. The anode rod is a sacrificial piece of metal which dissolves more readily than the steel tank. It lasts around three years. Your hw tank is lined with glass. But the seam on the side of the tank is welded after the tank is lined, and so the glass melts. So, to make the heater last a long time, drain it once in a while, change the anode rod once in a while, and keep the temperature low. There are only three manufacturers of residential water heaters in the US: Rheem, State, and A.O.Smith. All others have contracts with these manufacturers. Read the fine print on the label on the water heater. They have all been in business for a long time. If one is worse than another, it won't stay that way for long, because it will lose business. State has a patent on a special fill tube that circulates the water and keeps precipitate in suspension, but big bucks. State has sued other manufacturers for infringement and won. Otherwise, as far as I know, they are all pretty much the same.

If you go with any sort of solar system, make sure it has a gas backup and not electric. My energy costs went up $100/month when I added our solar system down here in San Diego. I am now getting it corrected with the installation of a small gas tankless unit, using the solar storage system as a pre-heater. If you're building the home then many of the traditional drawbacks of tankless don't apply to you. You can build in the correct gas line and venting from the start. If I were in your shoes I'd probably go tankless (30 percent tax credit this year -- see the stimulus law or visit www.energystar.gov). If a single unit won't handle your demand then get two. And plumb it with the small tank system (10 gallon) for recirculation and to overcome any sandwich problems. This approach has been detailed in this forum somewhere.

My Rinnai gas tankless water heater has a built in recirculation feature. My furthest bathroom is 50' from the tankless. The shower is hot within 8secs of turning it on. My recirculation pump is on a timer and is programmed based on my family behavior. I was really concerned after reading so many of the reviews online about tankless water heaters topics like temp sandwich and not being able to use multiple showers and appliances at the same time. I have low flow shower heads in my bathrooms from Grohe and Hansgrohe. Two of my bathrooms have thermostatic valves. The third has a very old pressure balance valve that will be replaced soon. The shower heads are rated at 2.5gpm. They perform really well. The tankless also has a feature to fill a bathtub,. I have used this once and the tankless worked like a champ and filled a 50gal tub in 9 mins. I have city water and will perform my first flush of the system in May. I was also afraid of the temperature drops as it got colder. We had a week of sub zero temps and I noticed no impact on the water heater. We can take two showers concurrently, run the dishwasher, washer and a faucet at the same time. My home has a crawl space and most of my plumbing runs through the crawl. The tankless unit is hanging on the wall in the utilities room. Just wanted to post another experience in tankless. One of the main drivers for going with tankless in my case was that I needed the space. The tank heater blocked access into the utility room and a wall needed to be taken down to remove the heater. I have a Rinnai RUR98i. Good luck!