Good programs cost money and are recognized by the BAFA. If you want a fairly precise statement about your wishes, I can recommend Buschbeck solar technology to you, since they also take your personal data into account when making an offer to determine the size of the recommended system. What you then want to do has to be worked out. Many programs of energy consultants are too general and do not adequately represent the performance capacity of a solar system for solar heating. I would not buy a solar system just for hot water. These are usually all guaranteed to calcify, unless you limit the temperature in the storage tank from top to bottom below the calcification point, which is particularly intensified from 60°C. Buschbeck has solutions for this that can certainly be viewed at existing systems. You are from Hesse – from which district do you come? You probably do not want to name your town, but that is also not necessary. If you want to get in touch, just write to me, then we can have a phone call.