I have done this sort of thing in the past using templating.

First I drew my design in Inkscape, where it is easy to do complex things. I put in bit of place holder text for the labels that would be replaced with templates later. When I was happy, I saved the SVG from Inkscape, and opened it in a text editor. I found my bits of place holder text and replaced them with with template tags.

Finally I wrote my script to load the svg with template tags, and replace those tags with the desired text from my database.

For that project, I used Text::Template, though you could also consider using Template::Toolkit which appears to be much more fashionable at the moment.