Consulting firm seeks asset accounting for a building cleaning company

I am a self-employed accountant and am looking for software only for asset accounting for a building cleaning company (with several hundred employees). I act as a link between the building cleaner and their tax advisor. I then prepare the relevant data for them and for further processing in DATEV.

The software should meet the following requirements:

• What is required by law + cost centers, cost units
• Two additional functions are desired
• Entry of the tax advisor's asset numbers, as these differ from the existing numbers
• Search function or sorting by both numbers
• The monthly depreciation (calculated) with corresponding cost centers and cost units is required, if possible in a format that can be imported into the existing financial accounting software (interface requirements are not known).
• Alignment with DATEV figures - cent differences.
• Windows compatible.

Two software workstations are planned.