(a)

the wifi module as below:(Name:AzureWave,  model:BCM94313HMGB),this wifi module is single-band wifi including Bluetooth.

(b)

We also have the second one wifi modele,name:Atheros, model:AR5B22,(dual-band wifi including Bluetooth),this one is a little expensive than the first one.

(c)

or you can choose this one, name: Broadcom,model:BCM43224HMB (300M dual-band WiFi without Bluetooth )