Is the 5.1.1 activated/unlockable for none official carriers, I'm using a iPhone 4 GSM model on 5.0.1 Gevey Sim Unlock
I don't think it is buddy. I think only the 4S can be unlocked like this.
If I was you, I would stay as you are, unless you really need 5.1.1 for something. As there aren't many changes in 5.1.1 from 5.0.1.
I have the same set up as you and I'm staying as I am.
I've just had a look on Gevey's wesite and it only covers up to 5.1 with certian baseband.
So the answer is it can't be unlocked with a Gevey Sim Tray.
Stay as you are on 5.0.1.