Two sources of materials that might be of value to builders in general.
Aircraft Spruce Specialities http://www.aircraftspruce.com
good supply of dope and other woods
Hang-em High Fabrics http://www.ecom.citystar.com/hang-em-high
Polycarbonate Coated Ripstop Polyester
This fabric is the replacement for “Icarex”. This is the lightest
and toughest material available. Use like other plastic coverings and
apply heat to shrink. Other lighter versions available that require dope.
Other items tow line, tow rings, etc