For SF Cremona: JF Concentra 1 or Plinius 8150?

My new Sonus Faber Cremona just arrived. I have a Plinius 8150 integrated amp (and a meridian 508.24 CDP). It was perfect to drive my former Signums. But maybe not good enough for the Cremonas. Pre + power solutions are too expensive for me. As it is the new Jeff Rowland Concentra. Within this framework, a second hand Concentra I might be a good bet. Is it? Or should I keep my Plinius? Thanks.
Stay with the Plinius. I have a JRDG Concentra I and think it's a marvelous product, but that doesn't mean it will out perform the Plinius in your system. I have not heard the Cremonas, but I have observed a strong family sound in their other products. Based upon your experiences, it's more than likely that the Cremona will also match up well with the Plinius. Take the time to let the Cremonas break-in and for you to get used to their performance capabilities before even contemplating changing any other components.
Jeff Rowland is not a good match to Sonus Faber. I have tried 2 times, 8Ti pushing Electa Amator II, and Concentra II pushing Signum. Never get good results.

Dynaudio, Thiel and Avalon are good matches to JF.
FWIW, I have a 8200 MK.1, which started life as an 8150 (was upgraded to 8200 by the US distributor). Have read various reviews claiming 8200 MK.I is a singificant improvement over 8150, and that 8200 MK.II is a big upgrade over MK.I. These claims are unverified on my part, have not done an A/B.

But perhaps upgrading your 8150 to 8200 MK.II would provide more of a good thing?

I did the 8150 to 8200 MkII thing also. I agree with Tim. The 8200 is a fabulous integrated and, for the relatively small cost of upgrading, you couldn't do better.
Don't laugh, but Krell 300il is supposedly a great match for SFs.