I wouldn't feel the need to stock rolls of housing. I use it so seldom and I have limited storage. I needed some this summer and my LBS was temporarily out of stock, so I bought some on line from Cambria Bikes. They sold it by the foot for a decent price and delivery cost. They sold ferrules and ends by the piece.

I certainly stock spare cables, even carry a spare shifter cable with me on tours. If your Trucker has road levers, it'll be a different cable end. Shifter cables are the same.