If a sail is to be made by a professional sailmaker, who is used to using polyester/dacron sailcloth, then the best choice is  Hayward Sailcloth, produced by Heathcoat Fabrics . It is especially made for cruising sails, is softer than "racing" cloth, and is treated to resist UV damage. It is made in white, but also in red, blue, cream ("egyptian cotton") and tan. In the Mediterranean, I would certainly want a coloured sail, to be easy on my eyes. My sails are made from the cream coloured cloth, and are easy to look at in bright sunlight. They have lasted for 6 years, 50,000 miles and 3 passages through the tropics without degradation, but the cover of my self-steering vane, made from Bainbridge cloth, was completely degraded during the same time period. One warning: the red and tan colours will tend to fade over time.

I would not employ a sailmaker who has not already made a junk sail - you would be paying for his first sail to be a learning exercise for him!

The only sailmakers we know of in UK/Europe who know about junk sails are Chris Scanes and Sebastian Hentschel. Of these, Chris Scanes uses Haywards cloth and will have already made several replacement sails for Coromandels.

But why not make the sail yourself? If your old sail is a satisfactory shape, you have something to copy.