Why not update? I unlocked mine before realising that it was 1.1.2 when 1.1.4 was current. Connected back to iTunes, did a Restore, updated and then unlocked it again. The software was rated for 1.1.4, so not a problem.
Just be careful about bying iPhones abroad. If you need a warranty claim, you have to do it in the country that you bought it.