IF it's possible you might be able to take the ISP SFP and put it in a SFP to RJ45 media converter and then you can use any 1gig capable router. I did this with my Telus SFP.
OPNsense or OpenWRT. I run multiple OPNsense firewalls for family members all connected together with a WireGuard Mesh.
Cisco is command line for the most part until get into the APIC NSX stuff. There's others but I'm only exposed to those 2 where I work.