Which heat pump? Circulation system?

Hi,
We are planning to build a KFW 55 NEO 211 Fingerhaus, we were proposed an air-to-water heat pump, unfortunately I don’t know if a circulation system is included. However, we also have the option of a gas absorption heat pump (correct me if necessary), what are the advantages and disadvantages of each for a house with 128 sqm?

Best regards & thanks

Fingerhaus advised us against gas because the technology is more expensive and one might need a circulation system possibly with recovery to achieve Kfw 55 again, and all of this are high cost factors.