Where can I find a database containing a detailed break-down of service
providers (e.g. accountants, lawyers, doctors).

My requirements are:
- Consumers oriented directory (e.g. Google directories).
- Comprehensive, heirarchical structure
- For each service, a list of associated expertise. For example, if we
take an architect the line of expertise can be interior design,
construction, decoration, etc.
- More refined than the NAICS system
- Features quality performance components for each service. For
example a medical service given by a doctor can be measured in levels
of: professional expertise, clinic, human relation, treatment outcome,
cost, etc.