Think out of the box (Multiple domains with WordPress multisite),
Generally WP “Create a network” option will give you subfolder or subdomains site. Here is how you can use the same “Create a network” function for multiple separate domains, one for each sub site, you need to use this plugin:
http://wordpress.org/extend/plugins/wordpress-mu-domain-mapping/
And follow these steps:
http://ottopress.com/2010/wordpress-3-0-multisite-domain-mapping-tutorial/
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