Wordpress Plugin ajax search with selection of result

I need for my wordpress page a plugin that offers an ajax search. I need for my wordpress page a plugin that offers an ajax search. The data’s for the search are in a mysql database outside the wordpress database. The search has to be at least in three languages the user can choose. The user can add single results of the search to a list. The User can select off the added results from this list anytime. The result is sorted by a additional field (different classes) and if one is added to the list, it has to be sorted there by this classes. In addition any class has some standard results which can then by added by the user if he choose one result with this class. If the user finished the selection he can a) finish the search and pressing a button opens a lightbox page showing the result sorted by classes b) go the next step within a form to order. In the best case the plugin can therefor be used alone or within a form. If it is resonable the project can be extended to a plugin for the complete form (5. steps).