Official Unlock after Jailbroken Unlock?
Return your phone to its standard state, so ios4.1 and then yes, you can ask the carrier to request unlock from Apple. 

The unlock works by changing a database entry for your UDID on Apple servers and therefore whether or not it's jailbroken should make little difference. With that said, to be sure it's all worked ( and because you are planning to) taking it back to a standard OS install would make sense. 

Hope this helps.