Wait wait wait, I lost you somewhere. You have a good road bike that you want to upgrade to a mountain bike? As much as I'd like to make a joke about any mountain bike being an upgrade from a road bike, I'm going to refrain since I don't actually think I understand the question. Instead, I'm going to just take it as "I want a mountain bike, what should I get?"

Hardrock and Rockhopper are both good bikes, as long as they fit you. Rockhopper will be a slightly lighter frame with nicer components and racier geometry, but either bike is more than competent. If you're from a bike friendly area, Craigslist might also be something to consider, since you can often get a lot more bike than you'd be able to buy new. However, it might be harder to find something in your size, and you need to make sure it's in good condition and hasn't been abused. Why don't you point us to your local Craigs?