We handle the black corrugated pipe. It comes in various sizes, probably you will want the 12" double wall (smooth inside) with end plugs. They are manufactured by ADS (Advanced Drainage Systems) www dot ADS-Pipe dot com. Some local Home improvement stores will carry it. They come in 20' lengths, we sell 1/2 lengths but most do not cut them. As a ref. you can figure aro $5 per ft. plus the end plugs.

Too expensive to ship that so local will be the best bet. I've used that before and works well.

Clayton