I use a
werner 13 foot folding ladder I bought on sale at Lowe's or Home Depot on sale for $79. A few years ago. I either carry it in the truck bed or laying on edge secured and padded with a shipping blanket in the main trailer aisle so it doesn't move around or damage anything.
I also bought a set of
Werner ladder pads I can slip over one end to protect anything I need to lean the ladder against.