Thinking of taking the plunge.

I have to agree with the Bluesound recommendations. 

Good sound quality, stable and intuitive app and good, quick resale if you get the bug for an upgrade. An upgrade might get you slightly better sound but chances are it won't give you as good a UI or software.

You have a nice DAC, so you can use the Bluesound DAC or compare it to your present DAC...and go with whatever sounds best.

If you start with an iPad, use the digital out and go into Settings to select hi res.

‘The iFi zen streamer has a lot of fans and costs less than Bluesound.

Also agree with bluesound node. I got one and was surprised at how good it sounded. The interface is amazing. My wife uses it sometimes and enjoys it. I later added a Schiit Ygdrassil and that really opened it up. You already have a nice external DAC so you'll be in a good place I'd imagine. 

+??? Newest Bluesound Node 2

I hate to say it again, but I will  - Bluesound!