Bilingual Website

What is the best to approach a bilingual website?

Can I have a wordpress within a wordpress?

I’m working on a website who main audience is in english but they want to attack the spanish market as well. The problem is that they want the exact webdesign and content in english and in spanish.

I was thinking on hosting the main english site (ie. http://www.xyz.com) with wordpress and creating a folder (ie. http://www.xyz.com/esp) and install wordpress there for the spanish version.

Is this possible or is there a better way to handle this.