Personally I run a Ubiquiti EdgeRouter
I can also recommend the Ubiquiti EdgeRouter as it is a pretty powerful commercial grade router at a SOHO price level. Much better than anything you will get from Linksys, Netgear and the like, especially with that many rigs.
I run a number of rigs myself and also think just statically assigning them an IP address is the best option. My internal network IP scheme I use a /23 block (512 addresses) and keep the lower half of the block for my non-mining devices, and the upper half for mining devices. This way I could name my miner according to their IP address. So my rig named miner01 would get the address 192.168.1.1, miner02 would use 192.168.1.2, and so on. So between setting them up as static addresses not needing DHCP and having a simple naming and IP addressing scheme, this works out well for managing larger (50+) rig type environments.
By segmenting your network this way and with a capable router such as the Ubiquiti, you can even go a step further and apply strict firewall rules on your mining segment to further protect your network. Since you miners only need to connect to a handful of Internet based servers, a handful of firewall rules will help keep any unwanted traffic from going in/out to your rigs. I would recommend applying some rules to your normal LAN traffic as well, but that is getting a bit outside the topic.