Of the products the OP is considering, in the $4K-$6K range, volume control (preamp functions) may have a bigger impact on SQ than the DAC, and an even bigger impact than the streaming functions. A couple of Chinese companies (Lumin and Matrix Audio) make a big deal of their hybrid (digital/analog) approaches to volume control. They offer interesting integrated streamer/DAC/preamps in the $4K-$6K range (or a bit higher). If you're in the USA/Canada and want to stick to North American products (for the service/support), then consider PS Audio (Colorado); Exasound, Bryston, NAD (Canada); Mytek (USA/Poland).
IMO, in the $4K-$6K range, with respect to streaming/DAC/preamp capabilities, you may not notice all that much difference in SQ (again, esp. w.r.t. the streaming). Maybe focus more on features/functions and on the after-sale service/support. With digital components, you'll almost certainly run into software/firmware issues. So it's a plus to have a company with a relatively big user base and a strong service/support presence in North America, the UK, or wherever you are.