In the end, we also ended up at Ikea. Installed with a friendly carpenter and a handy friend - everything great. Ikea appliances are decent, the refrigerator hums a bit louder than hoped, but it is perfectly bearable. With furniture and appliances, we ended up at 5,200 EUR, plus 800 EUR for the installation as described, which also took six full person-days. The installation alone would hardly have been possible (alone because of the loads to be lifted and support work). Installation through IKEA would have cost 1,800 EUR by the way. And now we are looking forward to our kitchen....