Just a few up grades?

Purchased a 07 ZZR 600 last summer.

Was thinkin of adding a viper exhaust bolt-on to it but then found out the bike has carborator and not fuel injection. Ive seem some reviews else where saying you should get a jet kit for carboratted bikes if intending to add aftermarket exhaust.

Question is, do i really NEED to get a jet kit if im just plannin on gettin a bolt-on exhaust? Is it gonna hurt the engine in the long run to change out exhausts and just how much difference would a jet kit in horsepower/performance?

Any help would be appreciated, THANKS  

Chances are you might be OK without it, but ideally a good jet kit will not only make more power via a better A/F ratio but it'll be safer as well. If your bike is too lean from too much air, it can cause serious engine problems.
I'd advise buying the kit and either have a shop do it or a friend that already has done one. Watch how they do it, take your time and you'll know how to work on it in the event of a problem. Also, look for some ZZR600 forums of ZX-6 specific forums for detailed info.

Thanks