ᐅ Which heat pump? Circulation system?

Hi,
We are planning to build a KFW 55 NEO 211 Fingerhaus. A air-to-water heat pump was recommended to us, but I’m not sure if a circulation system is included. We also have the option of a gas absorption heat pump (please correct me if I’m wrong). What are the advantages and disadvantages of each for a house with 128 m² (1,377 sq ft)?

Best regards & thanks

Fingerhaus advised us against using gas because the technology is more expensive, and a circulation system with heat recovery may be required to achieve KfW 55 standard, all of which are significant cost factors.