Hi Aspose Team,
Yes, you need Aspose.Total for Java in your case.
First of all, Aspose.Email can be used to extract attachments from email message. Once attachments are extracted, Aspose.Words for Java can be used to convert Word documents to PDF, Aspose.Cells can be used to convert Excel documents to PDF and Aspose.Slides can be used to convert PowerPoint documents to PDF.
As far as first pages of the PDF should include header, subject and body are concerned, you can convert your email message to PDF. This will generate a PDF with header, subject and body. You can use Aspose.Pdf to merge any PDF (after converting attachments to PDF) with this PDF.
Please feel free to contact us in case you have further comments or questions.