Don't buy a combo streamer/dac. Dac technology is still advancing and you want to be able to swap it out when something significantly better comes along - and it will!
Building a great digital system requires that you start with a great front end (garbage in / garbage out). Forgoing discussion of routers, modems, switches, Wi-Fi, etc, your streamer makes a big difference. But, streamer technology is pretty stable, so if you get a high quality streamer you can likely move up to any future new/improved dac WITHOUT COMPROMISE.
The Lumin U1 mini is a very solid choice. Even better is the original Lumin U1 with its separate linear power supply. I think The Music Room has a pre-owned U1 for ~$4500(?) (MSRP ~$7500). It's a top-shelf unit- Roon ready, and exceptional connectivity options allowing for future upgrades s to your system.
Get one of these and you can concentrate on the rest of your system journey. But always, always optimize your front end first if you expect to hear the full impact of your downstream changes.