Integrated Amp for Silverline Prelude II

Used Krell KAV300 or KAV400 could be found within $1500. They're very easy to use and sounding great.

I have a pair, have yet to hear anything that they do not sound good with ! Personally I would look for a used Rega Brio, but as I said Preludes are not fussy about either amplification, interconnects or speaker cable.

That said, I would avoid AVR receivers as they won't do justice to the bass a Prelude is capable of.
A truly great speaker.

Schubert - that would be a good price point. She would like the remote. Also thinking about a Plinius 8200, but it would probably be too pricey....

Indeed, too pricey and not needed.

If the speakers indeed are not fussy, and even if so, the Marantz PM8004. Sounds great with all the speakers I have. Have not used it with your mentioned speakers. The PM8004 is a really sweet amp.

Yes, could just as well go down in Marantz line as well.
I usually drive mine with an 8 watt a side Eastern Electric tube integrated. Works great.

I am very impressed with Audio Analogue amps. Superb quality and workmanship and a very musical sound. I own the Maestro Settanta Rev2 and that amp would work wonders for your Silverlines. For less money the Puccini would also be an excellent match. I simply cannot count all the amps that I have been through in my long life as an Audiophile, but the Audio Analogue has been (by far) the best. Just do a Google search and you will certainly be impressed. I no longer own Silverlines, but my AA amp makes my Ref 3a DeCappo-i's (soon to be BE's) just open up with cathedral like soundstaging with gorgeous musical tones.

My 0.0238 cents
Tubeears

Tubears, AA amps do sound good, but that stepped volume control on many would drive any non-audioplile nuts, it did me on the one I owned . The Easterm Electric I replaced it with was also big step up in sound.
I still use the AA Bellini pre as a phonostage.

Thanks all for those good suggestions. I will keep my eyes open for any of these products on the used market. I think any of these might do well, and none are too expensive.