I tend to use straight fletch myself as well.....though when I was using fixed blade/replacement blade broadheads I was primarily using offset fletch. The offset fletch tends to help stabilize the arrow more so than the straight fletch but not quite as much as a helical. If I were in your situation I would try the straight fletch to see how it works for you. If it does not work out then simply take the arrows to one of the local shops in your area and have them refletched with one or two degree offset.