AMoRE is an experimental campaign to search for neutrinoless double beta decay of Mo-100 based on mK thermal calorimetric detection with crystal scintillators and MMC readouts. We are building a new low-temperature detector system, AMoRE-II, containing about 500 detector modules for a total Mo-100 isotope mass of about 100 kg. Each detector module consists of a target crystal of Li2MoO4 with heat and light sensors for simultaneous measurements of phonon and photon signals. In this presentation, we report the progress of the sensor development and the module arrangement including the sensor performance results and the design concerns for such a large low-temperature detector system of AMoRE-II.