the question I have is how often are you really going to want to change forks?

I'm not a good person to answer this question because my road bike works on just about everything for me. The only problems I really have had off-road with my road bike were on a rock garden. Then you probably want high ground clearance. Not so sure a suspension fork really buys you that much there, I guess I'll find out when I get my bike going. I am also building myself a mountain bike frame which will start out with a suspension corrected rigid fork.

Since it seems you are talking hardtail, people tell me it's best to limit the travel on the fork to 100mm