Lots of good info here from others. Here is my advice based on my experience, FWIW.
Get two Outlaw Audio monoblocks if you have the room. Previous generation monoblocks (Model 2200) are awesome and have a low height profile. Their new generation (Model 2220) are taller but also very good. High power Class A/B, and you get separates.
I am also looking to go Class D myself, and I am looking toward the high-value proposition of Buckeye Amps. Buckeye sells a stereo amp based on the Hypex 252 module for half of your budget. Or if you want a Purifi stereo amp you might have to go a bit above your budget.
If you’re looking for more than just amps, though, (like an integrated amplifier that has a DAC, a volume control, multiple source inputs, etc.,) then none of the above suggestions will help you. There are a TON of options for integrated amps. I have experience with used Parasounds (various models, but he original A23 is excellent.) But again, there are a TON of good options if you need an integrated amp; see others' comments or be prepared to devote a good amount of time researching on the internet and/or YouTube if you know who to trust or just to see if you can find a consensus on some models and brands.