A Kickstarter would be a bad idea for OBS, since its release model doesn't really fit with how OBS is made. People have suggested it in the past, but I don't think that's quite the right fit in terms of crowdfunding for OBS.
Pretty much all development right now is being done on OBS Multiplatform, which is for Linux as well as Windows and Mac. There is a lot of work that applies to all 3 distros at the same time, so there isn't really any use in donating for a particular platform. But if you want to make a general donation, I know it will be appreciated.