Amplifier upgrade for PSB Synchrony's

About to buy Synchrony Ones. I have a Simaudio I3RS (I3 but a bit more neutral and refined on the top end), but I am looking for something that will bring out the best of the Synchrony Ones - meaning more resolution through the midrange, deeper bass extension and better bass grip.

Decided against pre/power due to space issues and need for more cabling.

I enjoy the Simaudio sound- speed at the top and bottom. My amp is 100W into 8ohm, 170W into 4ohms.
(1) new Simaudio 600i,125W into 8, 250W into 4.
(2) Accuphase E450
(3) Plinius Hiato
(4) ATC SIA 150 or NAD M3 or M2 (think these will be far lower level than the others)

Thanks for your help