I always used a sleeping bag and carried a light blanket to use in case being inside the sleeping bag got too hot. I used a huge over size sleeping bag, large enough for me and the wife.
On my bed at home... But in my OTR days, while training I used a sleeping bag. It's just easier for the few weeks needed. In my own truck I used sheets and blankets. Easier to wash when dirty, easier to remove in the middle of the night, etc.
I purchased a memory foam mattress from mattressfirm and it was like a foot thick.. Best sleep I ever got in a truck and I usually sleep under really thick blankets.
Tuft and needle mattress, sheets and a thick comforter-oh, and Mike Lindel sent me one of his pillows. lol