Yes, DNS servers are added under general setup. Try using whatever dns servers your ISP was handing to you under DHCP since you know that works. Otherwise Google's DNS servers, 8.8.8.8 and 8.8.4.4, are reliable and reachable from almost anywhere. It doesn't matter if you allow DHCP override because you're no longer using DHCP.
What gateway are you adding? Use whatever gateway your ISP gave you under DHCP.
Any reason you are switching to static IP?
Steve