C# .Net SOAP Webservice to access accounting database form MSSQL

Need to write Visual Studio C# application with SOAP Webserice for accessing the accounting program database. The application needs to be packaged into windows install program that customers can download and install on their server. The application needs to have a simple configuration to setup database details via ODBC. The Webservice will need to provide some basic methods: - get product price and availability - get product description - get products list - get invoice list for customer - get invoice details - submit order The database access layer needs to take into account that several versions of the database may exist so each version should have a separate driver that accesses the specific fields. The data access should work by creating database views which expose the fields we need in the web service for read purposes. The writing of data should have good error messages for data validation. For now we only need one driver and will provide a sample database for development and testing.