Class D Integrated Amplifier Recommendations.

I too, am using PS Audio M700 mono blocks on a pair of Magnepan 3.7i's.  More than enough power, sounded as good, if not better than the Bryston I was using before.  As someone mentioned earlier, the M1200's are a hybrid class D and have had rave reviews, as did the M700s.  If you don't like them, send them back per their policy.  You even get 14 days to return - if you find a used pair in The Music Room.

NuPrime Evolution one is a excellent class D monoblock amplifier. 

NAD M23

Aavik

I have a suggestion but maybe over your price limit unless of course you find a used unit. I am using a Bel Canto E1X int. amp. It has dac, streamer, preamp, headphone amp, phonostage(mm & mc) plus 150 watts per channel into 8 ohms. It removes a lot of cables, lightweight, and uses very little electricity. Plus it comes from a company with a lot of experience in class D amps and a fine reputation. Just my opinion of course. 

you can check out apollon audio. 

I had their purifi stereo 1et400a and really enjoyed it. highly regret selling it a while back, and even contemplated buying another one again recently. however, I decided to give another amp/brand a go and pulled the trigger on a nad m23.