Step-up from Node2i for native AmazonHD streaming?

The Node 2i is a great streamer value (no real competition anywhere near its price range) particularly if you connect it to a good DAC. If you want to up the performance, there are non-destructive mods that allow you to use a higher quality SMPS from ifi or a LPS (ebay has a lot of excellent reasonably priced LPS options).

If you’re set on wifi, make sure you get it from a place with a good return policy. A lot of people don’t have issues but there are also a good number of people with issues. I had to switch over to a wired connection with my 2i after suffering wireless issues (the 2i is right next to the router and no other device in my house has similar issues).

Starting a new thread, because I've realized Node2i doesn't have necessary coax input (for connection of CD player) - not enough inputs.

You may have painted yourself into a corner with all your requirements. What you’re looking for is a streaming DAC, plenty of those out there but I think what’s going to severely limit you is native Amazon HD. I’ve heard this a lot regarding Amazon HD integration. I don’t know if it’s Amazons fault, or that of the manufacturer’s, but either way it ends up with Amazon HD not playing nice with most native streaming platforms. 

Apparently either Amazon is being selective with the UltraHD API (who gets the right to use it), or mfg's won't pay the licencing fee, or some other API-related issue. I have a suspicion it will become more widely universal as time goes by. Sound United companies (Marantz/Denon/others), Bluesound/NAD, and many others were able to implement spontaneously on (some very old) pre-existing hardware with firmware updates, so the hold-up seems to be Amazon API rights availability.