This first time jb'er needs some advice

[Hustler]

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So I've had my phone for a long while now and have decided I wanna jail break it. I have a windows computer, iPhone 3GS on Att, version 4.2.1 (still!), firmware 05.15.04.
I've read through guides here from time to time but I'm not exactly fluent in the lingo or processes like most on this part of the site!
My first has to do with shsh. Found this thread below and it talks about if you're on 4.3.1 or 4.3.2. Since I'm on 4.2.1 I still need to manually save my shsh right?
https://forums.macrumors.com/wap/GetThread.php?t=1139441&f=105

Now I'm on iclarified's website and it's asking me if if I want to use redsnow or green poisen to jailbreak on 4.2.1.  The difference is as quoted "If you have an iPhone 3GS with a new bootrom you will only be able to perform a tethered jailbreak with RedSn0w. Use Greenpois0n for an untethered jailbreak on iOS 4.2.1"
Am I going to have a new bootroom? From what I've gathered, I'd rather have a Nontethered jailbreak. 
http://www.iclarified.com/jailbreak/iphone3gs/windows.php?firmware=4.2.1

OR is all of this irrelevant and would it be best just to update to 4.3.3 and just jailbreak that? 

My end goal is to get PDAnet for tether for when I get an iPad for light tether away from the house.  (I've been following the threads regarding that too, hoping someone comes up with an update or more info to be truly undetectable).   Also just minor things like widgets and a theme change. 

Thank you for any help/advice on the matter.
Brad

 

[Hustler]

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.

 

[PsstGreek]

Which ever software you use to jailbreak your iPhone, it will be untethered. Both Redsn0w and Greenpois0n have to been updated.

You're going to have to save your SHSH manually. TinyUmbrella it still having issues getting the SHSH from Cydia.

 

[Hustler]

Thanks for the advice
As far as saving shsh manually, does that mean that tiny umbrella won't be the method I would go about using to do so? Or does that mean that Cydia won't Work with tiny umbrella to get the shsh? If not tiny umbrella how, because that's the method I keep finding in my searches.

Also, should I get 4.3.3 or just jb my 4.2.1? Any pro's or cons to going 4.3.3. The main reason I held off from 4.3 updates is because unheard about worse battery life, but I've read it's not an issue anymore with 4.3.3.

Thanks,
Brad