Search database using data assist pages

I have built a dynamic website for estate agents. Using Data assist I designed all the needed pages both renting and buying properties.

After successfully building the site, I know need to create a search which enables the user to specify weather to search for renting or buying properties.

My problem is that the search fields would be different for each search, I am trying to find a way of allowing the user to specify whether to search for rent or buying, and need the form elements to change for each search.

How can I do this and is this possible using any of the web assist software.

The easiest way to do this would be to have two different tables that store the rented and bought properties and then run through the DataAssist Search Wizard for each of these. Then you could have 2 different pages that the user gets forwarded to depending on if they're renting or buying.