I doubt you can go wrong with either of them. The Kona has a better fork, the Rocky (likely) has a better frame. I say likely because the 2003 Fusion and Trailhead are no longer hand welded in the BC factory. They come to Rocky from overseas, and are then inspected and painted at the Rocky factory. Also these two models no longer use Easton Aluminium.

Try them both and see which one you like better. Me, I'm biased, I'd go with the Rocky.

Kris
2002 RM Trailhead

PS - do you have the Rocky CD? If not ask your LBS for it, it might help you make up your mind. Even if it doesn't, it's fun to watch!