Cost of shipping a dimensional object wide makes this something to make on site. A roll bender, 2 steel pipe and 6 pvc pipe are the main materials. The larger the diameter the higher the yield in the area.
DIY - How to install a drain pipe from the gutter of your house to drain to your backyard. Pictures of the concrete, burying the pipe, digging the trench, sand backfill and PVC pipe. Material list and prices.