More on central heating and hot water

Ages ago I rambled on about our thoughts for central heating and hot water. It is an expensive part of the rennovation, plus it will make life expensive, hard work and uncomfortable if we get it wrong. Oh the pressure!
Since then we have read even more on the internet. It seems that a lot of systems like we are thinking about have two water tanks, an accumulator for the heat from the wood burner, which is used for central heating, and a smaller tank for DHW (domestic hot water - got to speak the lingo you know) that is heated by the solar thermal panels. The DHW tank also has an electric emersion heater for when the sun doesn't shine enough. We are keen to have free heating and hot water so this arrangement doesn't exactly suit us. It is not clear whether we could heat the DHW tank with heat from the accumulator in the summer. It is possible to do as I described before and have the solar and wood burner feed the accumulator and not have the other tank, however because the accumulator is something like 2000l (the DHW tank is smaller at maybe 200l) the solar panels are unlikely to heat it hot enough so you have to burn wood all summer. This isn't terribly efficient for just hot water as you are heating a much larger volume than you need. Another alternative is to use solar to heat the accumulator as much as possible (which is likely lukewarm) then have further heating as you use the water, called 'on demand' or 'in line' - this can be electric or gas.
While reading about all this I came across people who, rather than use solar thermal for their DHW, use solar pv. The solar pv generates electricity and this is used to heat water either via a heat pump (ground or air source) or via an immersion heater - or more likely a combination  of the two. There are a lot of discussions about whether solar pv used like this is in fact more cost effective now (as it gets cheaper to install) than solar thermal. This is interesting to us because it would mean we could harness the effort free energy from the sun rather than the effortful energy from wood and it could provide the heating as well as DHW. However of course these systems have their complexities (and costs). In general heat pumps are better suited to creating warm rather than hot water, which means they are well suited to underfloor heating (which we have assessed to be too expensive) but not so much to radiators or DHW. It seems though that they can do higher temperatures as the systems get more sophisticated so we are investigating further.
My head is spinning after reading so much on the internet. It is hard to find people in the same position as us. Most people are happy to use some electricity, as the system will still work out cheaper than gas or electric heating. However for us our most basic heating is wood which is free, so the other solutions aren't saving us money - only effort. But that is important too, as there is only so much work it is realistic to think we can do each year with the animals, the growing things, the maintaining the property, perhaps the earning some money, and hopefully the having some time off and enjoying ourselves! There are of course people out there doing similar things (I am not a beautiful or unique snowflake) but I haven't managed to find any very detailed descriptions of the systems they have settled on.
I am sure you will be hearing more on this subject.