Desktop Application Development for a mid size Real Estate Business.

Thanks for reading. We need a software development for a mid size real estate business. The business now it's using excel files to organize their info. They have 2 real estate proyects with over 1.000 operations made each one and they will have more projects. Software requirements: 1. The software must organize the different data about each real estate operation. 2. It has to manage each client information plus client's contact information. 3. The software will have to work in an offline network with about 20 PCs running Windows XP. 4. Each software user has to have an username with password. It has to identify each operation movement with the user who made it for control purpose. 5. The information managed by the system will be confidential. The software must be estable and very secure. 6. The software has to be easy to translate. We will provide you the information in spanish and english (if it is needed for comprehension). The final software has to be in Spanish. General requirements: 6. This job will be commercially confidential and full copyright in your work will vest in us. 7. You will have to deliver us the source code used. In order to apply to this job please specify how will you fulfill those needs, wich programming language you will use and relevant information.