content in the database is completely under your control, just author the site content in Spanish and force the site to use to use Spanish resx resources and number formatting. resx files control labels and button text. resx files live in the App_GlobalResources folder and the spanish ones are named like .es.resx or .es-MX.resx for Mexican Spanish.

by default the web browser language preference would determine which resx files to use but these keys can force it from user.config

<add key="site1culture" value="es-ES" /> this controls numbers and dates
<add key="site1uiculture" value="es-ES" /> this controls the resx files used

the only problem might be how up to date and complete the Spanish resx files are, I'm not sure how good our current Spanish resx files are. You can update them and populate missing keys if needed and forward the resx files on to me for inclusion in the project.