We use FOP for document-shaped stuff, and it's worked out pretty well for us. But I could see using SVG when you want a single page with complex layout (esp. ro

We use FOP for document-shaped stuff, and it's worked out pretty well for us. But I could see using SVG when you want a single page with complex layout (esp. rotated text, etc.) For an invoice with a couple of fields filled in, you could also consider using a PDF form. (And use a library like iText or pdfbox to fill it in.)