I think that most of this can be done directly in the DataAssist wizard. Select your table then choose to create only the search and results pages. When you are configuring the filtering for the search within the wizard do not set anything here, it is better to do this after the pages are created. When you are configuring your results page there should be a check box to include the search form on the results page. When you finish the wizard you will have a search page and a results page with a search form on it, both search forms should be the same.
After you have the pages like this you can then go into the DataAssist Search server behavior to setup the search criteria like you need.