Web Service (SOAP)

We need some skilled professionals for create a Simple Web Service (SOA) for e-commerce transaction, database can be MSSQL or Sybase, work with XML. Must be reusable in any way Secure (across to HTTPS with Authentication option) Please send me little description diagram (of how do you actually perform this kind of services) and the CV o background experience in this area, payment must be done in 50% at reception of code, executables and documentation and 50% with the system in the production environment. Documentation of the final product is very important. Handle of the Spanish language is a plus.