I have a '03 jaguar and a '08 saber. What I want to do is change strings. But I would like to go with probably strings that are pre-stretched. Does helix make them? I don't know if zebra makes the size I need. The reason I want pre-stretched is because of new peep sights I've put on them, and you know as the string gets a little use you have to realign the peep. Sure would like some feed back from you guys! Please!