Any decent quality HI-Fi stereo amp will work. If it has treble and bass controls, just center them and igore them.
I use a Rotel.

Crown D75 would be great. I'm just not sure why you wanted those speakers? I hate them. I'm not sure whether Bob Clearmountain liked them or not? He Used to put toilet paper over the tweeters! You may want to also? Personally, I'd just flush those.

DC 300 series II user
Ms. Remy Ann David

I have NS-10's and I also use a Crown amplifier on those.
I actually like them, but it's best to have a couple of different monitors.
You won't hear a lot of low end on those, and they sound kinda midrangy.
But like has been said, if it sounds good on NS-10's it will sound good anywhere, there's some truth in that.

Hi, here is a frenchy that just bought the crown D75-A and I pretty glad with the sound, compared to my old DENON PMA-1560.

It's sharp, more direct and hitting (don't know if it's a good term).
the stereo image is also better and more accurate.

I have two units, the second is to amplify my INFINITY SM-115. I hope to change them with a pair of ADAM S2.5A... A sweet dream...

Bryston 2b.

Bryston... another price...

I've tried them with a few different amps and I like the way they sound on a cheap consumer grade Yamaha RX-530 from the 80s. They sound fantastic... extremely natural. Maybe because they were consumer grade speakers at the time and made to be coupled with this generation of amp. The Crown's match up pretty well too if you're keen on something more pro. Just my 2 cents. :)