Any unadulterated SUT with a turns ratio of 1:10 (i.e., a voltage gain of 10X) will show the cartridge a 470 ohm load if connected to a standard MM phono stage with an input resistance of 47K ohms, which is the industry standard and has been for probably 80 years. These are laws of physics. So price is not an issue; a cheap SUT will yield the desired impedance. To achieve a higher impedance, you must use a SUT with a turns ratio of less than 1:10. Then do the math as described in my post above. But 1:10 seems perfect for your needs.
It actually would be a simple matter to open up the chassis of the Icon and find out what is really going on, then fix it so you end up with the cartridge seeing 470 ohms, but that is assuming that their other information stating the turns ratio is 1:10 is correct. We don't even know that for sure. So yes, buy something else.
By the way, I don't understand why you would indict Soundsmith. They can only reiterate what is in their package insert, that their cartridge wants to see at least 470 ohms. There is no reason to expect PL to be an expert on the Icon.