As far as I understand it, you'll still need a player to access the music on the Melco, as it's purely a network device. The alternative seems to be to use the N1a with a decent USB DAC connected to its USB port, as I've seen it used in one or two recent reviews: I think this is a new feature Melco has added recently.
If I recall correctly, there are other NAS units able to be connected straight to a USB DAC in this way, though it's not something I've looked into as all my music is networked. However, I remain skeptical that the device upstream of a USB DAC can make that much difference, and for the same reason I don't know how Melco/DAC would compare to A.N. Other NAS/DAC, but provided you can find an amenable dealer it could be fun finding out!
So that's a Melco at £1600, a good 24/192-capable DAC at, say, £300-500 (although cheaper USB DACs are available), and whatever you need to spend for a decent amp, just to replace your UnitiQute. If it were me, I might be thinking about upgrading the UQ to 24/192 and adding a power amp as an alternative route.