I agree that there is nothing wrong with the 20A induction board. I have one setup for annealing. I looked at the component redundancy, form factor to mount coils and add fans. I chose to focus on the 50A board. The RPS-750-48 is a great power supply but at $169.00? It has far more capability than the cheaper power supplies I used. I had looked into the RPS-750-27 upped to 30V output and using you resistor setup to dial in the amps. I may still experiment with that power supply. The point I make is that there are additional ways to " skin the cat" ... no best or absolute way. Use whatever works for you.