o2 Payg problems

Hi,

I want to use o2 payg on my iphone that has been unlocked on iliberty+.

The problem i have is when i go into settings/general/network there is no edge option to enter the settings.

Also, i have been told that i cant send emails from mail unless its an o2 email account.

At the moment im using orange payg and it works flawlessly and can enger edge settings also , but i want to go to o2 as the data bundle is better.

Any ideas on how to overcome this?

Matt