"a highly capable, yet sensible streamer" and "My interest ...is due mostly to their ripping feature ...I have a couple thousand CDs."
It sounds as if you are interested in a server/streamer with an easy CD ripping feature and also on-board storage of digital music files.
IMO, considering the number of CDs you own, you are smart to look at the convenience of the ripping feature and you should also look at the convenience of managing your digital music files once you have them ripped files, i.e., will you be able to log in on any of your networked devices and manage your files?
You should also look at what you will be using to play files, i.e., are you planning to add Roon and use that to manage your streamed and stored music or will you be using another streaming program/app, or perhaps a proprietary program unique to the streamer manufacturer?
Also consider whether you want a single box that sits in the same room as your primary music system or whether you might be interested in a separate server and streamer. If you connect your server to your local network, you then have the option of using multiple streamers for different music systems in separate rooms or even a garage/outdoor system.
It appears price is not your primary consideration since you have named a couple of $6K+ streamer/servers (Innuos ZENith and Aurender N200). If your budget can expand a little, you might also look at Grimm MU1, or even MU2.
Another one to look at would be a server from Small Green Computer in conjunction with a streamer from Sonore (or another streamer). The nice thing about Sonore's streamer line is not only that they sound good but that you can start with their lower priced ultraRendu Plus for only $1K or opticalRendu for $1.6K. If you later choose to upgrade to their Signature Rendu SE Deluxe Optical at $5.4K, you can move the lower priced streamer you started with to stream music in another room. Both SGC and Sonore offer very good support, IME.
Take your time and read these threads to learn as much as you can before you make your decision.