unlocked iPhone on Rogers?

[Sparta]

I want to get an iPhone (doesn't have to be the 3G model) to use on Rogers. I don't have an mobile Internet plan, but if I unlock this, it should not be an issue right? It would still work with my SIM card? If I do accidentally use 3G or EDGE, do you know how much Rogers is charging? Also, what's a good way to unlock an iPhone? Are there ways I can download over the internet that are free? (I use a Mac.)
If I do use an unlocked iPhone, can I still use sync iTunes music, Address Book contacts, iCal events, and download from the App Store? Would I have to avoid Apple's iPhone updates?
Thanks for any help.

I also want to know if I can disable 3G or EDGE.

[Unregistered]

I am not aware of a free unlock method for the mobile model that you have specified. I suggest you can approach Unlock-zone.com and specify the country,locked network of iPhone.Based on the availability you can get the permanent unlock service along with free instructions. Once unlocked you can access other phone features without any problem. To know about the charge rates and to disable you can call Rogers and get the idea.