Custom portlet for support case stats that permits on-the-fly filtering within itself

I'm new to portlets, not to scripting.

Basically, I want a portlet that has 5 dropdowns (ultimately should be multiselect) and when I hit Submit, it runs a few searches (likely via Suitelet) and displays the results in the same portlet AND still shows those same dropdowns and the submit so I can resubmit without having to refresh the portlet or the page.

With a Simple Form portlet, it's easy enough to display the fields and the submit button as well as loading a first, default set of results from the search queries (these are put into a table that's loaded into an inline HTML field as part of the simple form. When I hit Submit, it calls a SuiteLet that runs the same query with the filters set on that form, and the Suitelet returns the results. However, the problem is my fields are gone now.