You mentioned Benz and Soundsmith. Many Benz LOMC cartridges have high-ish internal resistance, like the Hana SL (33 ohms). So those are just as difficult to match with your phono stage as is the SL.
Specifically, these Benz models are: Gullwing, Ruby, and LPS. They share a ruby plate armature which significantly lowers output level relative to any given coil arrangement. They're a tough match to a SUT and OP's phono stage. Typical for these is 0.35V @ 40 ohms or 0.7mV @ 80 ohms.
The lower Benz lines use an iron cross armature that is much more efficient. These work great with the right SUT, and should also be workable with OP's phono. The models include: Ace, Gilder, Wood, Zebrawood, Reference, Ebony. Typical for these models is 0.4mV @ 12 ohms or 0.26mV @ 5 ohms.