I know that one of the major browsers, and maybe just one version of that browser, will redraw the page when new headers are returned. But if you cannot guarantee that your users will use that browser, either IE or NS, then this solution is not viable.

You may be able to do something with JavaScript, where your image is returned and then hidden when the results are returned.

I do not understand why you believe the HTTP redirect will not work. If you are concerned about the user having to wait an extra 9 seconds (when using a 10 second delay) then decrease the delay to 5 seconds or even 1 second.