Java Webservices Application

I'm looking for a developer who can create a Java application that must be able to run on any platform (Windows, Unix, Linux, iSeries, ...) and communicate to the clients using Soap. The application contains a local database (preferably XML) with approximately 12 tables having all kind of data, that on request is exchanged using the Soap interface to the clients. For example, the get damage code request returns all the damage codes from the local database, while the get repair code returns only the repair code for the given damage code. The most important factor here is that the application must be really fast and be able to run on any Java supported platform. In a next phase we will create maintenance screens to maintain the data in the local database, in the first phase we will supply the data in Excel format If you have good skills in Java development then please reply. Note that we will evaluate the provided application constantly to ensure quality.