little confused with unlocking 3gs phone

[chronoman]

i currently have a jailbroke untethered iphone 3gs.
I want to unlock to other sim from orange .
I was following recent tut and was ready to install but dont want tethered or loose my gps .
Is there any way doing this or am i just getting confused.
I got cydia on iphone currently.
Any advice appreciated
forgot to add firmware 05.12.01
cheers chronoman

 

[Kryton]

maybe this will help: Unlock Baseband 04.26.08, 05.11.07, 05.12.01 and 5.13.04 With Ultrasn0w | jailbreak