+1 for the Avantco 3500W, 240V.
I purchased one of these before getting a BrewEasy system. It worked great and the only reason I went away from it was to get some more process automation.
As far as pot size, I am guessing they are concerned about the weight. Since the heater works by magnetic fields, the pot does not have to contact the induction heater. You can support the pot separately. I've seen pictures of oversized pots supported by 2x4's with the induction heater slid under, but not supporting the pot. My pot fit on it perfectly so I did not have to do this, but apparently it works well.