What unlock to use?

[momija]

Hi. I currently have a jailbroken & carrier unlocked (blackra1n) iphone 3g, on 3.1.2, with 5.11.07 baseband.
I want to update to OS4.2.1, and found this comprehensible guide: click for external link
However, as I was reviewing the guide, I seem to get stuck on step 8.
I got confused whether to update my baseband (currently 5.11.07) to 6.15 ipad baseband or not. Do I have to update to 6.15?
What unlock do you suggest for me? (and jailbreak too, if you have a better guide than the one posted above)
I am using Windows 7, btw.
Thanks for the replies.

-Jaja

 

[momija]

Oh, nevermind. Found an answer to my questions.
http://www.iclarified.com/entry/index.php?enid=12949
http://www.iclarified.com/entry/index.php?enid=4253

 

[Myzhi]

Since you current baseband can be unlock, don't install the hack iPad baseband since doing so could cause GPS problems and you can't ever restore with official firmware file. Instead, find (google) and create (pwnagetool) a 4.2.1 custom firmware (one that keeps your current baseband). Afterward, restore through iTunes with that custom file. Once done, install Ultrasnow, from Cydia to unlock.