Bigger fuel tank for kz200

I have been riding the hell out of my kz200 but find it quite annoying to have to stop and get gas as much as i do. Is there anyone that knows if a gas tank from a larger kz would fit? I dont mind doing some custom fitting and fabricating parts if need be. I'm just not to sure about the bar it sits on as it seems like it would be quite a bit more narrower than bigger bikes. This is my first bike and my first bike project. I was just wondering if anyone had ever done this. Any help would be much appriciated. The tank on it now holds an astonishing 1.8 gallons. :woohoo: