OpenOffice::OODoc isn't going to help you much there. At least not natively. You could, I guess, use OpenOffice::OODoc to extract the XML contents, then use XLST to generate attractive HTML, XHTML, or XSL-FO. But at the end of this, you're still going to need a program of some sort to render the markup into PDF.

The program I know of to render ODS is OpenOffice itself. It works quite nicely. You can either use the built-in Export to PDF function, or you can Print to a PDF-capable virtual printer, such as the Adobe PDF printer supplied in the commercial Adobe Acrobat (v7) package.

To automate this process, we use OO macros, called from outside of OpenOffice. If you'd like help on that, I'd be happy to send you the required macros & mechanism for calling from Perl. Drop me a line at jeunice EMAIL illuminata DOT com