I have an ISR4331 that I’m using to replace an average branch office environment. You need to watch out for a clock issue, but not all of them are affected by it and a reputable seller is a must. Most also include the licenses you need so no extra cost there unless you need more services. I don’t run a FW yet because my lab doesn’t have Internet access, but I’d go for something from Sophos.
I have an ISR4331 that I’m using to replace an average branch office environment. You need to watch out for a clock issue, but not all of them are affected by it and a reputable seller is a must. Most also include the licenses you need so no extra cost there unless you need more services. I don’t run a FW yet because my lab doesn’t have Internet access, but I’d go for something from Sophos.