my 2008 trek 7.2fx has proved pretty tough in terms of rough terrain. I did some mountain biking with it back when I was 110kg/242lbs and the stock wheels and tires have held up fine.

IIRC they still use 35c tires - that's perfect for rough gravel roads, so you should be fine.

IMO the suspension of the DS series is overkill, but I ride 80% on road 20% off so *shrug*