The longer the repeat, the more variety in the hexagons. In the book, OBWs are made with repeats as short as 6", many prints out there are 12" so your 14" repeat will work just great. You can make the strips any size you want, but 3 3/4" will work with any size repeat. I think this size was chosen for maximum fabric usage, allowing for a bit of wiggle. Cut the strips any width you want, just make sure that you use a 60 degree ruler. Also watch as you cut the triangles and if it looks like you are going to get repeats of patterns you just cut, cut a waste strip of half an inch or so (at 60 degrees) This will reposition your ruler.