I've been liking fse racing sheet and regular swiftcord. Two ways to make em:
1. Eye splice ends and use a small spectra (dyneema) strop to the clew.
2. At mid point of sheet, splice a small spectra strop through the sheet and attach to clew. You then need to either tie the ends together or dead end them at the corners at the back beam. I just tried that last night and liked it. I noticed that some of the top euro f18 guys were setting it up that way.

Another option could be NE flight line, but it has some polypro which I personally don't like. I am finding the polypro sheet the came with my boat is burning up fast.

Cheers