If you click on this page:
and click on the Solution Recipes tab, there is a section that talks a little more about using DataAssist Search.
But to answer your question, you don't need to use the DataAssist Wizard to use the Search Wizard.
If you already have a form and a record set, then you can just launch the DataAssist Search Wizard, and on step 2 you will select your search page and the form and on step 3 you can the different search criteria.
If you have any further questions, please post back.