integrated amp recommendation needed

There is a difference in the quality of watts. A Yamaha or Cambridge 100 watt amp will sound quite a bit different than a 100 watt amp for on Levinson/classe/McIntosh. That's why Revel wants you to use a quality amp for their speakers

There is a Plinius 8100 integrated amp here on audiogon. Looks very sweet for $650. Get a nice power cord and good speaker cables and I bet you would be in sonic heaven. There are also some sweet tube amps there too....Cayin, Jolida and Eastern Electric. Those tube amps are much more powerful than the rating. I know I have a Line Magnetic Audio push/pull and it sounds like a 100wpc amp.

Of course if you wanted something new, I would increase my budget $50 and get the Bluesound PowerNode 2.
An amazing product that could really transform your system. I have the Node 2 and the MQA playback is astonishing.

http://www.bluesound.com/en-us/products/powernode-2/?cl  

What about an ayre ax 7e?

Save more money.

The Plinius 8100, 8150 and 8200 are excellent if you can find one in your price range. They are getting a little old, but should still be good for at least a few years.  If/when they need the caps replaced,  do it and still have a good,  inexpensive amp.