Mcintosh MC402, Krell FPB 600 or Passlabs x250.5

Hi guys, need some advice on the above power amp option.

I'm currently using a pair of Sonus Faber Olympica II. It was placed in bedroom and only driven by Krell 400xi.

Now the setup has been moved to living hall and I'm getting a pre-power amp to drive the Olympica II as the krell 400xi obviously doesn't have enough juice. I've tried it with krell 400xi in living hall and the bass extension is just not there, even though I do like the soundstage, smooth mid / high that the 400xi is able to produce with the olympica.

Recently I came across a used Mcintosh C40, and it was always in my wishlist to one day try the mcintosh gear. I bought the C40 and now looking for a power amp to pair with it. Naturally, it would make sense to match Mac Pre with a Mac power, but I would like to open up for more option.

I know each of those three are distinct in their power rating, but I don't always listen at loud level. I listen to all genre of music, but probably spend more time on vocal songs.

Does anyone have experience pairing them with Sonus Faber with great result? In fact all of them cost about the same (I found used unit in my local dealer). Or there's other candidate that I should consider also?

Thanks!