What used amp should I pair with my newly acquired Monitor Audio GR60's?

At that price point I have found  the Jaton Operetta AV 5140 to be an excellent all-around performer.  I prefer a more detailed sound with sharper image focus/outlines and a tighter bass.  These Jatons are frequently available in 4 or 5 channels so you could use 1 amp to biamp your speakers, which is exactly what I did with very good results.  

Sonically, these amps are (for the price new) quite detailed and rather neutral though the bass may stand out a bit, not being exaggerated, but having more weight and slam than many I've heard.  I think power rating is 70w/8ohm  140/4ohm and has been plenty for me with several speakers with average efficiency even when played quite loudly.  

For what they sell for on the used market, I can't imagine you could do much better.  There is an upgraded 2 channel one on USAudiomart for only $300!   And in all honesty, I felt it bettered a Cambridge Audio 840W which I'd been using until I got the Jaton.  The Jaton was a bit more detailed and seemed more transparent.  Both are monsters in the bass department.  Appearance-wise, especially in pics, they do look like very little more than a small step up from some A/V receivers but in person, they are quite substantial.  For the money, I think you'll be very satisfied.

thanks.  I will look into it.  Someone else mentioned I should check this out:  https://www.usaudiomart.com/details/649730297-belles-soloist-5-amplifier-completely-refurbished-all-...

what do you think & how do you think it would compare to the other?
thanks. 

ring30----what amp did you settle on?

So, right now I'm using my Pioneer Elite VSX-52TX as a pre-amp.  Taking in the digital from either my PC or ChromeCast Audio.  Going pre-out to a Yamaha  RX-777 I picked up for $50 on Craigslist. I pulled the couplers on the Yamaha from between the pre-outs to the main-ins, and ran the pre-outs from the Pio to the main-ins on the Yam.  So I bypassed all the circuitry in the Yam & using the Pio to control the volume.  I also turned off all the speaker outputs on the Pio to reduce heat & other electrical interference as much as possible & running in direct mode on it (not sure if it makes a diff when running through the pre-outs on it).  It sounds great.  I still want to do some A/B comparisons. 

I also picked up a Denon 4311 just because it was dirt cheap around me.  Going to play with that also & try & compare.  Not sure it will be worth trying to do some bi-amping or try-amping with any of these configurations, but I thought I might try it with the Denon since my bi-amping zone 2 speaker outputs aren't working on my Pio.

Currently looking into an Emotiva UPA-200 someone is selling locally here for $175. Not sure if it's worth it or not yet.

Got any thoughts or opinions on any of that?
Thanks.