Hi BigLug,
I think that you can convert your PDF template into PostScript, than replace your variables by real data and convert PostScript into PDF again. Maybe it isn't very elegant way but it's one of many variants.
Michael
I agree with this. PostScript is fairly easy to read, is text based, etc. You should be able to take a template postscript file, make the text subsitutions in it, and then run it through some sort of PostScript to PDF (or gif or...) converter.