I have Kef LS50's and have been on an amplification upgrade path since I have owned them. I originally had my vintage Nakamichi TA-3 driving them, but planned to upgrade. I tried a Rogue Sphinx v1, but it seemed a bit dry. Tried a Musical Fidelity MS3i, very musical, but underpowered. The M5Si is actually a pretty good suggestion. I finally settled on a NAD 375BEE integrated, nice warm sound, lots of power. Then I bypassed the preamp in the NAD with a Schiit Freya, this was a huge upgrade. Finally, for now, I upgraded to a Coda #8 power amp. Another major upgrade.
My recommendation at a minimum, is to get a Freya S for a preamp, unless you want the tubes. I don't use my tubes often. The Freya is A (for sound/value) rated by one of the main hi-fi mags. Then choose your power amp. I have never heard Emotiva, but just a hunch you can do better. I really liked my NAD, maybe the 298 or Audio Advisor has an open box 275BEE that would work as well, though these are discontinued. Used Parasound or Hegel would be great, or even better, choices as well.
I do not play my music loud (any more), but my Kef's still need a lot of ready current, and the heft to drive 4 ohm speakers.
Let us know what you decide.