One airport extreme as DHCP server, two more as bridges, using Ethernet,
Use the switches built into the AirPort Extremes if possible. This will increase network speed.
However, you don't have to use Extremes purely as switches. You can use an inexpensive 5-port Gigabit switch.
As long as you use a Gigabit Ethernet switch, you can install the device literally anywhere you want downstream of the main AirPort Extreme router if you need more ports for Ethernet devices. Otherwise, use the Gigabit Ethernet switch that is built into the AirPort Extreme to keep things simple and minimize the extra connections that would be required using an outboard switch.
Be sure to use CAT5e or CAT6 Ethernet cabling throughout the network.
Is it best to place a 5-port switch upstream of the bridges, or, use the 3-port switch built into the bridge?
