Is 600 Watts good enough for this system?

You need to try to set what error message it gives you. Google how to disable auto-restart when BSOD occurs and the next time it happens it will tell you hardware or driver or just codes like 0x0000001e which you can google up to find a better idea. You seem to have a lot of fans but that shouldnt really add it up...and you didnt tell us your power supplies brand, sometimes this is a deciding factor a big name brand would rarely give you problems unless you push it to the limits but everything here seems like the 600 watts can handle it. but get back with us on your brand. thanks