Your schematic will work but im not looking to go that simple (not saying its bad) BUT that is a perfect example of what i said in my first post. It is something I would build in two days without much design thought. I want to build this one professionally and take consideration into all the detail of pfc and other small aspects. It should be easily a 600W power supply when its done and I dont want it to draw 800W total for inefficiencies in the design. I would also like the output power to be as clean as possible (little ripple). If I add more components such as snubber circuits, pfc, and resonance, then it will be much more efficient and reliable. Too many times I build these things and they work but get steaming hot and eventually a component gives due to stress because i didn't implement any extra safety components. One big thing I'm not sure on is the frequency to operate at. I have seen them operate as low as 20khz and high as 200khz. Most of the time 30-50khz. I did some bread boarding and find 40khz works good, however i'm not sure if it is the optimal frequency. I know as the frequency goes up problems get greater ( transistor configuration, heat on the transistors, less efficient, diodes unhappy) but the reward is more power output in less space. Its a balance.