Using the iPad firmware is very risky mate.
Firstly you can never downgrade and will be stuck on iPad firmware forever, secondly, you will loose your GPS.
If you run F0recast on it, it will tell you to that you can JB the phone and to unlock it you need to install the Ipad firmware, but that's bullshit as no current software will jailbreak your phone, to add to the pain all mainstream support for the 3G is practically dead.
Is there any reason why your mate can't call the network provider and get it unlocked properly?
I feel like I'm missing some other info here, but I'm not sure what it is, lol.
If you run your phone through F0recast, it will give you extra info about your baseband, this number is critical and decides whether or not you can upgrade, IIRC, if the last digit is more that 8 then you are in shitsville.
I think.