Hi, I0ve used iText some time ago, and generate not trivial reports is not-so-simple (it has its own API to draw elements inside PDF), but it's much better (and lighter) than many other solutions ... so good luck.
One idea: what do you think instead to generate your report as a real PDF file (maybe a temporary file), and then let the Client Application ask to the Desktop default application to open it (instead of having to handle the display etc inside your app) ? Comments ? Bye, Sandro