You have 2 easy options -
If you purchase the Icon PS1 you would need to buy a SUT wth 1/10 step up ratio and plug it into the MM input. There are plenty of vintage units such as Denon AU320 or Denon AU340 that will do the job. Alternately bobs Devices are a company that build SUTs, get good reviews, and they can advise you on the appropriate SUT to buy.
Second option is to buy the Soundsmith MCP2 phono. This has fantastic loading options and will match your cartridge. I have compared this phono, using a Soundsmith Paua, to some much more expensive phono stages, eg Lamm, Linn Uphorik and others and it is a very good phono.
Personally in your instance I would recommend you buy the Soundsmith MCP2, it's very good and will save you a lot of headaches. They also come up second hand from time to time if you want to save some money.
It is unfair to blame Soundsmith for not knowing what is inside the Icon. It is clear from the comments by the Icon designer that they have chosen a fixed 100 ohm ;had for MC cartridges based on recommendations from Ortofon.