I received a compact sportster for Christmas. I tried a Williams peep on it but decided to go with low power scope instead. If you go with the peep you will have to have a much taller front sight. I tried the tall front sight off my Versa Pack barrel and it worked great at 25 yards with the peep a couple marks below half way. You can get the VP front sight from Numrich, or many other front sights available.
Be warned about removing the front sight on a new barrel. Some have an adhesive on them that needs to be heated to get the thing off, some don't. Like most things it's all in the FAQ.