If you are handy with a sewing machine and have time, Sailrite sail kits are very good. They have designs and specs and do computerized cutting of the cloth sections. They sent along step by step instructions which surely added to my knowledge of this craft. I built a trysail last year that came out really well and is built with quality sailcloth and misc parts. I was able to put the time in to make sure the sail was well built and what I wanted. I will not hesitate to build another sail this way. It prompted me to go buy an old rugged commercial sewing machine (pressing your luck trying to do this on a home machine although possible) which I now keep right on the boat for repairs.
Alberg 35: With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship.