iPhone 3GS, best way to get newest unlockable firmware

[rrrodeybreaker]

Hi everyone,

This is my first post but I've been hanging out this site for a while now. I hope someone can point me in the right direction.

I am selling my sisters iPhone 3GS. It is running firmware 3.1.3, iBOOT 359.3.2 and baseband 05.12.01. I know that with this combination I can jailbreak and unlock the baseband. My goal is to run the latest version of iOS (ideally iOS 4.1) and still be able to unlock the phone (I'm not going with the iPad baseband - not an option). I hooked the phone up to TinyUmbrella and it got the SHSH's for 4.2.1 and 4.2b3. I'm on Windows so I cannot personally cook my own firmwares.

What kind of advice can the great readers here offer?

Thanks!

[Simon]

Stay where you are unless you are ok with a tethered jailbreak. If you have to restore for any reason you will be forced to go to 4.2.1.

[rrrodeybreaker]

Thanks for the quick response! And I love the sig - go LA!

[Simon]

Thx