I say go hard-tail. If you can already ride that terrain on your rigid, you'll be fine with a suspension fork. Just having that makes a huge difference. You'll also get more quality for your money. A decent hard-tail with a nice fork will make a Very capable bike. Heck, the difference between my mid-90s rigid and the same bike after adding a decent ~2000 era suspension fork was night and day. I can blast down rocky terrain and smaller drops now.