Carlos,
I make sails for the Daysailer. We are on the sailmaker list on daysailer.org. We also have a website,
www.slosails.com, a large Daysailer specific section will be coming soon.
You were asking specifically about a jib.
Here is how we build them. 5.5 ounce Challenge squareweave cloth with a huge mylar window. Our sail window is 24" tall and runs almost luff to leech. Finally, a solution to port-starboard incidents. You and your crew can really see.
A DS jib from us costs $340. They are very nice and will last you a long time. All sails come with roll bags.
-Karl
Sail fast, take lotsa chances.