Alternative to storage ovens, replacement storage ovens

Well, you always have 2 options: 1. Make heat generation as efficient as possible. 2. Reduce heat losses wherever possible. Of course, the best is to do both in combination, but if for whatever reason you are tied to storage heaters and no other heating/heating method is an option, then you just have to invest all the more in insulation: facade/interior + exterior, windows, exterior doors, top floor ceiling/basement ceiling, ventilation system, etc. etc.... Therefore, it would be practical to have more information about the house and the equipment.

We do have the topic of building sins .... night storage heaters are part of that. In my opinion a case for renovation.

Do you have to consider anything later with a wall heating system? How is it, for example, with furniture on the exterior wall where the wall heating is installed?

Regarding the costs for the 160 sqm living area. Is the following calculation realistic or naive?

Underfloor heating:
Retrofitting (50-70 euros per sqm): 12,000 euros
New flooring (50 euros per sqm): 8,000 euros
Total costs 20,000 euros
plus the heat source 15,000 euros?
Gas boiler?
Does an air-water heat pump make sense in such a property?

So approximately 35,000 euros in total

Same costs with wall heating, or is it more expensive or possibly cheaper?