A moving coil is generally loaded 10 times it’s impedance. The Hana EL for instance has an impedance of 30 ohms, so 300 would be a good place to start. Hana recommends loading the EL @ 400 ohms or greater. I own it and i run it with a Jensen SUT which incidentally has an impedance of which the cartridge sees of 430 ohms. This particular cartridge sounds wonderful any where between 400 a 475 ohms. Lower (numerically) impedance loading will result in an accentuated bass response and the cartridge will sound closed in. Higher loading will result in a brighter sound but also more open. My Rothwell mcx SUT will provide a fixed load of 100 ohms, ideal for many a moving coil, such as my Goldring Eroica LX, which the manufacturer recommends it be loaded at 100 ohms.
I do not subscribe to loading a moving coil at 47k, I reserve that for my many moving magnets.
What is neat about my pro-ject tube box DS2 is that I am able to dial up any impedance loading so desired on the fly from 0 to 1000 ohms.