Interpretation of new heating and hot water system for a 1970 holiday home

No, I wouldn't do it myself either; I just want to prepare everything in terms of planning to be able to put it out to tender and compare offers. It's difficult to get an overview of everything. The counterpart would be stylish with Daikin. They only write that the same capacity is sufficient for 50m²; if I go strictly by the capacity and convert BTU to watts, it fits again... but it consumes more... the black wall unit would be nicer again... but pay 1500€ more for that??

I wouldn't do it myself either, I just want to prepare everything from a planning perspective in order to put it out to tender and compare offers

Companies do not like to install material from the internet, as there should be a warranty, and you don't get that with cheap Chinese junk. I would have a company come, design everything, and create an offer. Then have 2 other companies submit counteroffers and compare them. Comparing individual prices from the offer on the internet is pointless.