Bad news mate, if ur baseband is 4.11.08, there's no gevey sim for it.
You need to downgrade to 4.10.01 and then use gevey. Now, you might also need shsh blobs for lower firmware.
There's a tut for downgrading from 4.11.08 on smashiphone.net
Hard luck dude. If you wanna wait, look out for applenberry site. They have meticulously mentioned gevey working with 4.3.5 but *with preserved baseband 4.10.01