All three GPU's should work fine on that PSU. The specs for the AMD cards say a minimum of 750W is required, but that's not really accurate. Unless you have a crazy amount of peripherals hooked up to your PC, 650W will be fine. Nvidia cards like the 970 generally use less power, so you could get one of those if you're still concerned about power usage.
Your PSU is a tier 4 (low quality) unit. It wouldn't be a bad idea to upgrade it after you figure out which GPU you want. Since your PSU obviously is working right now, I would use the money you have for the GPU. In a little while (after you've saved up some more money) I would recommend upgrading the PSU to a better quality one.