The 2007 is fuel injected and thus has no jets to change. You can change the slip on and it will have little effect on the the air/fuel ratio of the bike due to the catalytic converter. If you remove the catalytic converter, thats when you need to worry about the air/fuel ratio and getting a custom map with a power commander. There are a lot of different options out there and we have plenty of clips on here with sounds so you can listen to them. The best looking exhaust for the 6th gen IMO is the Laser exhaust... but you won't be finding those in the US anymore for purchase. Next to those, the Staintunes sound the best IMO. What you will have to do though is find what is pleasing to you, both in sound and aesthetics.