Best route to go for new dac?

Op, there are so many choices and everyone has their favorite. I suggest you avoid the "measurement" trap, the lowest SINAD numbers will not equate to the best sound. Audition a few that have a well put together analog stage and choose what you like to hear.
In a resolving system, the DAC is much more than a chip. 
Ignoring the sales pitch at the beginning, this video is worth watching to understand the importance of the analog stage. 
https://www.youtube.com/watch?reload=9&v=McoA82-fi9s

Best route to go for new dac?

R2R Multibit for a real sound and make sure it’s got a volume control, to go direct into amp with, as many including me think it sounds better with better transparency and dynamics,
Cheers George

Topping D90 , get the one with the MQA decoder if you like MQA. 

I agree that a DAC is much more than a chip. Because sound can vary, you really have to listen for yourself. Hardly original advice, but it's true.

The Topping D90 is well within your price range, it measures to perfection, and user reviews I've seen have been glowing. Apos Audio will let you return it within 30 days if you don't like it. The D90 would be the first thing I'd try.

Have fun!