Well, you can either go valved, classical A or A/B, or one of the stunning new generation of class D.
It's heresy, but I'd go class D. Hypex N-core has the real lead in this, and an increasing number of high end manufacturers are using them (Bel Canto, ATI, Nord etc). Distortions 0.0002% (2 parts per million), frequency, power and load independent. https://www.diyclassd.com/audio-amplifiers/ NC400 is the unit.
580W into 2 ohm, 400W into 4 ohm and 200W into 8 ohms. And it will drive down to 1 ohm, quite important for the balky load that ES speakers can present. Output impedance 0.6 milliohm. Discrete balanced input (can be configured for single ended). 125dB S/N - it goes on and on.