Making a difficult decision

@audiomaze, hint6 is great I have heard it. It is a good all rounder. Integrates are hard to compare in my view. What is more important for you?. With hint6 first few watts will be Class A. Not sure if that matters to you. 

Your speakers are 83 dB/1 W/1 m @ 4 Ohm btw. I am not so sure if 200 watts top spec will be enough. To reach 100 dB SPL peak(s) at 8 feet you need 200 Watts but that is too close to peak of both the amps. Sitting closer helps I think. 

Peachtree nova 300 has good measurements, low THD well into 300 watts at 4 Ohm. Can't find any for Peachtree nova 150 though. Which Parasound are you referring to?.

I am on the fence regarding Class D or Class A/B amp too. But I am looking for just a long time amp for now.

You could also try this:
https://www.stereophile.com/content/rogue-audio-sphinx-integrated-amplifier

Measurements are good all the way to 200W @ 4 Ohm.
https://www.stereophile.com/content/rogue-audio-sphinx-integrated-amplifier-measurements

@audiomaze, wrong comparison, nova150 working well for Paradigm is not the same as working well with your speaker. Paradigms are 92 dB / 89 dB and are stable at 8 ohm (if I remember right) very easy to drive and they have been like this for sometime. They driver based speakers. I have a pair of Paradigms studio 40 v3 version very easy to drive.

Do you know the lowest impedance level your speaker will go to?.

Check out Sanders amps , top notch and built for electrostatics : 
http://sanderssoundsystems.com/products/amplifiers/esl-mark-ii-amplifier
http://sanderssoundsystems.com/products/amplifiers/esl-mark-ii-amplifier

Try used market for such amp. You may be able to get something and have spare budget for an excellent tube preamp.