Help me select a cable modem and router

I’m in the US. I have Spectrum internet service so I have limited choices on cable modems. I currently have a Netgear C3700 combo cable modem and router. It has worked well for 5 of the last 6 years. Since I started doing a lot of home automation and adding devices my network has become very unreliable. After plowing through logs for hours I rarely find any smoking guns. Spectrum techs have been to my house and made measurements but say I am well within parameters for 1G service (I only pay for 100 Mbps). And when the internet dies it is almost always cured by rebooting the modem/router. But I have reason to think that the real cause is too many connections to my inadequate router.

I’m ready to bite the bullet and buy a new modem and router (or combo). The approved list from Spectrum is:

Arris SB8200
Arris SBG8300
Netgear CAX80
Netgear CM1000v2
Netgear CM1100
Netgear CM1200
Netgear CM2000
Netgear Orbi CBR750

Some of these are modem only and some are modem+router. I’ve been doing my own research and reviews and specs don’t paint any clear pictures. Most of my existing equipment is Netgear so I am inclined to stick with that brand but not entirely marrried to it.

I think my approach will be to buy a high end Netgear cable modem then get a router (not necessarily Netgear) that supports many dozens of devices. I currently have about 43 connects and expect to have a couple of dozen more soon. The Netgear specs brag about having 45+ devices connected and that is concerning.

Bottom line, I’m looking for cable modem suggestions from the above list and also a router that can handle 100+ connections and hopefully far more. SNMP, multicast, and other management features would be nice and I’m willing to pay for.

I’d not go exactly this route… If your ISP limits number of choices, I’d go for the simplest modem capable of handling required bandwith and then go for high end router. The rason is that all connections that goes through the router to modem are visible to modem as single connection. You do not need anything special on this component - this is just bridge between Internet and your router. Simple example; I had lots of problems with ISP provided Technicolor 7200 router/modem and I just set it to ‘bridge’ (well, since it has UPC custom firmware it is not possible to have pure bridge, it is still router, but with all possible functionalities disabled) and connected my own router (that in such scenario can be whatever you want) and all my problems gone! Having decent router allows to configure you network the way you want.
Personally I’d recommend Draytek routers, I’m using varouis models for 20+ years and replaced to newer models only to be able to handle higher bandwith I’m getting from ISP. Though these are a bit on expensive side…

It’s not a fantastic line up they’ll allow but if you have to go that route avoid Arris. My ISP provides an Arris free of charge and it’s shocking. It’s in modem only mode and plugged into a pfsense box because the router is just so bad. Clunky slow interface, restricted settings, poor design choices (non-obfuscated password in web UI). It’s just a really poor unit all round. In modem only mode it’s great. Very solid. But the router is an F-

Thanks for the suggestions. I ended up keeping the modem and buying a new Netgear RAX120 router. I’ve been watching the SNR and power levels on the cable connection for a few days and they are actually pretty good. My thinking was that I just needed a router than could handle a large number of devices. It arrived today, I spent about an hour setting it up, mostly because I could not completely remove my old router/modem from my network so I had to keep switching things around because they were fighting each other for address space. But, bottom line, my speedtest results are at least 3 times higher than they were. I’m getting 235 Mbps whereas 70 was good previously. And the network is very stable, no dropouts at all but it has only been a few hours so, fingers crossed. The problem was clearly related to the number of devices. Even the high end routers I looked at say they should be limited to about 50 devices. That’s a limit that I think a lot of HA enthusiasts are going to be running into very soon.

Edit: Yes, that’s an expensive router. But I got it for almost $200 off because it supposedly has cosmetic defects. I can’t find any!