Create PDF on-the-fly with any PHP library, based on our des

We need to dynamically create a invoice type of PDF when a user checks out/purchases on our website. We have a design, in PSD, that we need this PDF to be based off. You're free to use either TCPDF or FPDF to generate the document. It's important that the document be generated as quickly as possible (we have a high spec server), so no XHTML to PDF type conversion will work. The document also needs to be as small (in size) as feasibly possible since we'll be mailing out many of these. It is not a complicated design and should take minimal development hours. If you'd like a screenshot of what's required before bidding, please inbox.