Network Config, DSL WiFi, Win 7 and Linux

I have a somewhat large home network with 18 computers. Many of them are configured as a high performance cluster network for running large mathematical models. Others are various servers and accessory machines. I use a private network behind an edge machine running Linux for iptables/dnsmasq/router functions, an edge switch, several internal switches, and all that through an ADSL gateway. More details available if you want them.

Now I want to add WiFi for some laptops (all running Windows 7) and a few smart phones on a separate subnet. The question is, How do I configure the WiFi? Should I set up a router immediately between the DSL gateway (modem) and the edge machine then plug the WiFi router into the router? Or, should I plug the WiFi router into the additional LAN ports on the DSL gateway (modem)?

Suggestions more than welcome; warmly appreciated.

 

Bump - I am also interested.