Travelling From USA to Brazil: Need Cell Phone

Hello,

I have a Nokia CDMA phone that I currently use with Verizon in USA.

I will be visiting Brazil in the next couple of weeks, and then Thailand in September and would like to have the use of a cell phone while I am in those countries.

My understanding is that I need to get hold of an 'unlocked' quad band cell phone and then, when I am in those countries, buy a SIM card from a local provider.

Is this correct?

If it is, how can I get hold of an unlocked quad band cell phone?

Thanks.