I did (more or less) what you want, with a different approach. See this example.
Basically I created a microsite with Code Igniter that displays a digital version of our business cards with links to mail and website. Below the card are links to downolad or mail the vCard (mail because Safari Mobile does not support vCard download).
The WordPress database is the source of all the information on the card. (That's what you wanted I guess) You could put the download link on your WordPress site as well. (Ok, I admit, not the most elegant of solutions)
I would strongly advise against using QR-vCards: there are compatibility issues. So, as an alternative we use a QR-code on our printed cards that links to the microsite (as described above). Also, some people will not want to add your data to their computer but just use it once, the microsite allows them to use the links without downloading the card. And finally, as a bonus, if you do it this way, you don't have to reprint your cards anytime some info changes; it's a lot more dynamic.
If anyone is interested, I'm willing to post the code somewhere, but don't expect it to work out of the box; it wasn't written to be portable.