Simple tmobile upgrading question!

[myke55]

im currently jailbroken and unlocked on Tmobile with the iphone 3G, with 3.1.2 and FW 5.11.07

i am wondering what is the highest bb and fw i can upgrade to with no problems at all. i dont need the absolute highest with a lot of work put into making it work, im just looking for the best working upgrade. and how would i do this?

also, will this restore my phone to like new again? or is there any way i can do the upgrades without losing any of my apps, videos, photos etc.? i know in my past upgrades ive had to sacrifice everything to do this, just wondering if times have changed ;]

[iYeow]

Nothing has changed, you should sync with iTunes first before restoring. The stock firmware of 4.0 baseband can be unlocked but you will not like it as it slows down your iPhone.
For 3G , I suggest you just restore to 3.1.3 and either jailbreak with Jailbreakme.com or redsnow 0.9.4.
You can use aptbackup or pkgbackup to backup your Cydia stuffs

[myke55]

so i shouldnt upgrade to 4.0 even?

[iYeow]

No, IOS 4.2.1 is faster than 4.0 but slower than 3.1.3. It is up to you.
If you want ios version, go for the final version which is 4.2.1

But no unlock at this stock 4.2.1 unless you restore to custom firmware of 4.2.1 to preserve your BB.

[myke55]

confused as hell lol.

i just want the latest so i can download apps that i cant with this fw. and also the latest updates would be cool. and i do not want to lose my unlock.