1st gen iPhone + New MBP + New iTune

I live in Canada and when the iPhone first came out, I went to the states to get one. I did not modify the hardware in any way, but in order to use the phone in Canada, I had to jailbreak it.
The iPhone is currently sync'd with my Windows and the iTune haven't been updated because I'm afraid that once I do, it'll require me to update my iPhone firmware. Further locking my iPhone and I have to jailbreak it again.

So here's the deal now

In iPhone setting>General i found these info:
Model MA712LL
Version 3.0 (7A341)
I am assuming the Version means the firmware.

I bought a MBP a week ago so i'm assuming the iTune in it is the newest version available.

I figure this is a good chance to sync my iPhone with my MBP
coz.... well i think mac should go together
but I don't know if I can still use my phone after i do that

I'm trying to avoid having to "format", or jailbreak my iPhone
does anyone have any idea?
or.... does anyone have any idea what I'm talking about?

if you dont want it to update your iphone, just disconnect from the internet, and then it wont know there is an update.

P.s i dont have an iphone, but this is what i would do. if its windows formatted, theres a good chance it will want you to re format before you sync.