Have you looked at "useresponse"?

http://www.useresponse.com/faq http://www.community.useresponse.com/responses/php-source-co... http://www.singularcore.com/ #This is the opensource engine based on php-zend framework.

For other alternatives look here: http://alternativeto.net/software/uservoice-custumer-feedbac... #Yeah, custOmer is spelled wrong ;)

disclaimer: I'm not affiliated with any of the products, just trying to help.