As other have said, if you are running the digital output from the streamer to an external DAC (whether a separate box or one built into your receiver/preamp/whatever), the sound will be the same. (Pace Sterophile and YouTube reviewers who will insist that bits are not bits,etc.)
That said, the real issues are cost, convenience, and reliability. If cost is your primary driver, the Wii device looks good (I've not used it), and surely someone has mentioned or will mention a Raspberry Pi with whatever software. If convenience and reliability are tops, scratch the Pi; the Wii likely still works, but you might also consider a used Bluesound Node -- the software is now mature, the device will index music on connected devices (such as NAS), it has a lot of control and connectivity options, and supports just about every streaming service known to humanity. (Note: Apple doesn't play well with non-iOS devices, but the Node does support AirPlay if that's a consideration.) All Nodes get periodic free software updates, mostly to support new services, as well. Again, I don't know how all this compares to the Wii, as I've not used the latter.
Most importantly, get whatever appeals to you, whatever you find convenient, simple, and intuitive. This is *not* something on which you want to save a few bucks only to be frustrated and annoyed when trying to listen to music!