I'll second Grady as another HCI guy saying do the blower first. But here's my thoughts.
If you have a stock motor that is running quite well, you have to keep in mind that an HCI kit will break all of the nice clean factory seals on the top half of your engine. There are a number of issues you can run into here, including broken bolts, leaking gaskets, etc. And that's just for the install. By comparison, the blower is not very invasive at all.
Comparing a Vortech or Procharger kit to a Trickflow or Edelbrock top end kit will yeild comparable results (probably favoring the HCI, but not by a dramatic level). So with the supercharger you get similar power, and potentially far fewer headaches. It's probably true that the HCI would be better in terms of longevity. But that might not be too much of a concern for an 80,000 mile car.