Ballast is still an issue when trying aerials, as they're very light. The foil is actually like thin, shopping bag plastic with foam ribs (that's why
the guy in the video chased his dogs off of it after the end landing!). They came with an optional, straw-like strut to brace the canopy open, which I
rarely use. You'd need a gruntier, (prob. gas), engine to loft "real" fabric foils.
They were originally made in Japan and sold in catalogs and on ebay. Now there are only Chinese knock-offs available that are much cheaper, but are said not to fly as well.
