Atma-sphere M60s. What preamps work well?

Just received Atma-sphere M60 MkII.2 monoblocks. Replacing Simaudio Moon W-5. They sound incredible using Sonic Frontiers Line 3 pre. Much more transparent and life-like as compared to Moon W-5, which I have always felt is a great amp! Is it worth it to pair the Atma-sphere amps with Atma-sphere pre? Also, I am using relatively inexpensive B&W CDM7SE speakers which sound great in this system. Any suggestions on other speakers that match well with Atma-sphere amps, or just stick with B&Ws and upgrade model?