Which is best step up for Fidelity Research Fr-7

I bought a Fidelity Research FR-7 cartridge and a Fidelity Research FR-24 mkII tonearm. On the opinion of FR specialists of this forum which will be the perfect transformers to mach this combo? I already own an Ortofon SPU T-1 step up which is fantastic with my Spu's, but probably the FR-7 needs dedicated transformers...by the way the turntable is a Thorens 124 upgraded by Schopper.
Regards, Dario
I would search in the fora for commentary on matching cartridge impedance to a SUT. There is a lot to learn in the archives. There have even been a few threads recently.

Fidelity Research made transformers to match their carts. The XG-5 had a "low" position (for carts like the FR-7) with gain of 34dB. The XF-1 L, specifically made for low output impedance carts like the FR-7, has gain of 36dB. They also made an even higher-end transformer by special order called the AGT-5X which would have been customizable for low output impedance carts as well.

Given the Ortofon SPU carts are also similarly low impedance low-output carts (even similar VTF), and I expect the Ortofon SUT was designed with SPU carts in mind, I expect you will do very well with your own step-up.