We have stayed at Cloudland Canyon and at Best Holiday Trav-L-Park. I highly recommend both.
From Cloudland Canyon you can take scenic hwy along the ridge (without the RV)
Or you can take Tn-193.
Best Holiday Trav-L-Park is on the other side of Chattanooga (Actually in Ringold, Ga) but it's closer to the attractions. It's also a nice park. Very friendly people run it.
I highly recommend the Aquarium, but if you're going to try to do the Ocean Journey and the River Journey in the same day wear your comfortable shoes. I'd also recommend you do the Ocean Journey first (to me it's the best). The River Journey gets long after about 3 stories.
I'd also recommend the IMAX. We went and saw Sea Monsters and it's not what you think. Our 3 year old GD loved it. She kept reaching out trying to catch the fish.
If you want something to do at night, the mystery theater is a good show and the food was good. It's very interactive (or not).