What are some high impedance cartridges?

I'd be more inclined to switch SUT and look for low impedance carts ;)
 

You’re right of course. Looking for a shortcut though just to play around with different carts…

The upper end Clearaudio & Kiseki pickups are relatively high @ 40 ~ 50 ohms.

Like @lewm mentioned, it's not just about high impedance - it's about hitting the right net output level coming out of the SUT (including losses from loading): you want to hit a range of around 4mV  to 7.5 mV.

The Benz Ruby plate models have a nice high 38 ohm impedance, but they also have an unusually low output for that amount of coil: only 0.34mV. I did not find satisfaction in pairing the Benz LPS (latest version) with a 10x SUT (probably 3mV after loading losses). It was much better with a JFET headamp stage. On ALL my other cartridges, I prefer a SUT over the active gain stages. 

The Denon 103 is very similar to the Benz LPS (40 ohms & low 0.3mV output level) and I guess some like to pair it with a SUT, but for me that wasn't optimal.

I'd pair a 10x SUT with a 0.5mV - 0.7mV output cartridge. 

Depends also on phono stage gain and linestage gain, if any, and etc. Many use the Denon or the Benz with 1:10 SUTs. I assume their downstream components make up for the lowish signal voltage.