Integrated amp for Sonus Faber olympica nova 1

Sharing your wife's aesthetic preferences in more detail will help. Her appreciation for Sonus Faber is a start. 

Riviera Audio Labs is well reviewed. It has a softer aesthetic and color palette.

An Italian amplifier - speaker pairing. : )

Riviera Audio Labs Levante Integrated

There's always the Sonus Faber Musica!

How about the Musical Fidelity M6Si integrated amplifier?  It sounds great and your wife should like its simple classic design.  

“Internally, the M6si is configured as 2 independent mono-bloc power amps with a separate pre amp. It is, in fact, a pre amp with 2 monobloc power amps that just happen to share the same casework.  The M6si has 220wpc. It has very low distortion, outstanding noise ratio and extremely flat frequency response. Its inputs are phono (MM/MC), 4 line level, 1 balanced XLR and 1 USB ‘B’ up to 24bit 96kHz asynchronous.  The M6Si combination of high power, high current and extraordinary stability means that it can drive any loudspeaker with ease”.  

I own this amp and like it very much. 

Musical Fidelity M6Si amp

You might find the Circle Labs A200 interesting. Here's a thread on Audiogon where owners share their opinions.

Seems like she warmed up to the sound when you switched to the Pass. She’s an audiophile! You should explain that the amp is beautiful because of the sound quality it provides.  I’ve heard that the Pass/SF combo is a good one.