A wireless network is plenty secure when using WPA or WPA2 for the encryption.
If your wireless network is an "n" only network, your iPad or any other device connected to the network can only be connected via "n".
If a network is a combination n/b/g for example, a computer or device that is "n" compatible will be connected via "n". A computer or device that is not "n" compatible will be connected to the network via b/g. A computer or device that is not "n" compatible will lower the overall network throughput which only affects the speed of data transfer between computers or devices connected to the same network. Most internet connections don't provide anywhere near the speed of data transfer that a wireless network is capable of between connected computers or devices.
There may be a 3rd party app that provides this and if so, you plan on doing what with it especially since the iPad is your only wireless device?