I would take the boss over the bullet any day of the week...Except that you said you could get the bullet for like $20+? If you have a stock set up, keep it cheap and simple and get the pipe with the most value$$$. Both will only give you moderate gains on your top speed (like a few mph) on a stock bike.
When you're really ready to step up your bike, then you'll want to drop some cash and get a REAL pipe that fits your set up. Not a cheapy stamped out one.