I've just completed a kite kit from Hang'em High Fabrics. The kit consists of pre-cut fabric panels, pre-built spars, and complete instructions and fittings. An extra rectangle of fabric is included for making a kite bag. The kit costs $50 and can be ordered on-line (Part KKC - Conyne Delta Single Line Kit).
The material is 3/4 oz. lightweight rip-stop nylon. It's somewhat lighter than the rip-stop nylon available at my local fabric store. The spars are fiberglass, made from arrowshafts. The main cross-member has arrow nocks at either end, which slip into metal rings on the spars before flight.
Overall I'm very pleased with this kit. With the included instructions and the manual from my 50's era Singer
Sewing Machine I was able to master the basic skills (i.e. sew a straight line) and assemble the kite in
about a day or so. The very thin material sews easily, and the sewing machine mechanism really wants to sew
a straight line (more so than a table saw cutting wood) so the sewing was not nearly the challenge it could
Two things: my kit was back-ordered, but was back in stock and shipped in a very few days; and I replaced my central panels (blue) with fabric store nylon of a different hue. The kit picture shows what Hang'em High calls "light blue". The finished photo shows "blue" ripstop from the fabric store.
The kite flies well and seems to be stable in high wind and graceful in returning to earth.