I have a KG1000-G and run it on a 30A continuous power supply. At 50 watts, I've never really seen it use more than 10 Watts when transmitting. It might go to 11 when I'm not looking just for that little extra (extra credit for the reference). Anyway, a 30A power supply should handle two 50 W radios, especially if you're not transmitting on both at the same time...which shouldn't happen very often if ever. But if you want to be sure, and plan on using both radios at the same time for transmitting, you could go a little higher on the continuous rating just to be sure.