Avoid Intel based solutions https://lookgadgets.com/articles/intel-puma-modems-list/
Almost all 32x8 (capable of 1 gig) docsis 3 modems are going to be puma based.
No reason not to get docsis 3.1 unless you are truly cash strapped. That leaves the SB8200 if you're ok with 1Gbe ports, or the S33 if you want a 2.5 port.