they are simply 2" ID black ABS plastic pipe, thats cut to the right size and the sides are rounded. the cutting of the pipe is really easy with a wood chop saw, just measure out the thickness of your rim, then add how ever much over hang you want. the rounding can be done on the car, but it will take some time.

basically if you dont have a chop saw for nice clean cuts, then yes the sushi rims are good. if you end up burning through them quickly, might be worth it to try making your own, plus you can try using the grey PVC pipe, it supposedly lasts longer (its thicker and heavier) and grips differently.