The SG-2220 will probably be a good fit there.
I assume you have a Gigabit switch in there on the LAN side?
If you needed, for example, VLANs for different hosts and were routing between them via the 2220 you would see some restriction. But if your only traffic through the firewall is to/from the internet there would be no problems.
Are you going to be running any VPNs? Packages?