for a rebuild kit you have to get the parts from a dealer or online, places like ron ayers or metricparts.com. there are crappy china kits out there on ebay do not bother with them as they will give you more issues then they are worth.
you can give sean morley a call from the forum here, he will have the the bits you need and also can supply you with a jet kit but if you dont have exhaust mods etc dont bother......
guys like him and dannymax can rebuild the carbs for you if your not up to it but really with basic skills and the use of the forum here(lots of articles on how to set up carbs) you should have no issues.....but getting a carb sync tool is a must and also the ability to set the floats correctly are gonna save you a bunch of headaches.