Hello I need the pros here to suggest me the best option... The problem now is my mum going to buy me an iPhone in Australia and there are 2 choices for me to choose from :

1) get the unlocked iPhone with 2.2 firmware
2) get the locked iPhone with 2.1 and yellowsnOw it later

which is better ?

If i choose the 2nd option where yellowsnow can make my locked phone to become unlocked, will this be TEMPERARY unlocked ? or PERMANENTLY unlocked ? Do I need to be constantly jailbraking before performing an update ? Or is it that after installing yellowsNow my iPhone is unlocked forever and i save $$ not buying the unlocked unit that will cost me additional $150 in Australia..

PLEASE HELP ! PROS..

also for some information, can i still install yellowsNow even my phone is already unlocked ? what are the extra benefits I can get from yellowsnow that I found no in unlocked unit ?