I have also ridden at KC and at Seven Springs. KC is a nice campground but the stalls can get wet and take a while to dry. The trails go from very pretty and scenic to areas stewn with trash. They are private trails and are not kept like a public trail system is. If you do go there, I would recommend a trip over to the Bankhead Forest which is only a 15 minute drive. You can easily get your big trailer around at the Pine Torch Trail Head.  I would recommend shoes as well.

 Seven Springs has some beautiful trails but, again, private trails and some just go right up or down the side of hills. When they put a sign up that says 'experienced riders only' it's probably down right dangerous. Not all of the trails are that way but pick and choose carefully. Your horse should be fit to ride there. The barns there are just panels under a cover for the most part which was fine. There are no trees in the camping area which wasn't a problem for us as it was Feb. when we were there. Nice folks at both places though and we did enjoy ourselves. At KC the camp sits up on top of a hill. We had some weather come through (Feb again) and sat in the trailer while 50mph winds rocked it....We survived though!  :)