Need a DAC Recommendation.

There are a ton of options, especially used.
Personally, I prefer NOS DACs.
Look into a used Metrum, MHDT or of you can find one, a Yamamoto.
Just my 2 pennies.

In this price range, I would absolutely be looking at a Denafrips Pontus II for $1700 US.

Border Patrol SE. Caused some controversy when it was reviewed. Why? Because it sounds great. Yup. That was controversial. In your price range new I believe and if not, just skip the SE part. Gary Dews makes excellent stuff. 

I recently connected a topping Topping d70s. I am absolutely thrilled with what it did for my system!

I have the Chord Qutest. It’s great. Not a bad review out there. I just added the Mscaler. Wow more of everything: Air, space, prat, bass, 3D. 
Qutest can be had in 9/10 used condition for $1300. Or spurge on a new one for not much more