Well, having the rear exhaust is cool. But, if your still looking for horsepower, then you need to find an exhaust that is tuned to that engine. Unlike 4 stroke engines, 2 stroke engines need to have a certain shape to the pipe, to help create horsepower. Stinger length, stinger size, how the chamber is shaped all effects the 2 stroke engine.
If all your looking for is the cool factor, and don't mind loosing some HP, you'll find something that will work. But if speed, and or acceleration is a must, you need to stick with a tuned pipe.
Hope this info is helpful.