I currently park my TT on a narrow side of my house. I have been debating extending my driveway along the opposite side of the house (quite expensive) to park the TT on when not in use, but now I am ...
Without knowing available gravel and the specific names used in your area, I would call a certified gravel pit operation and ask them what type of rock is used directly under AC paving. That is the material that I would put down. With the right amount of moisture, a 6-inch lift can be wheel-rolled to a nice smooth and compacted finish.