Hi Chico,
Right off the hop go to Boardgamegeek and get the latest rules and set-up for Global 1939 (if you have not already). You will need to set up an account there to download the files. They will tell you what you will need for pieces. From what you are saying, you may need/want more (e.g. Axis Minors, more neutrals, Communist Chinese, Holland, coastal subs, battleships, etc. and so on).
For a view of the first Global 1939 map produced there is a cool video on:
http://www.youtube.com/watch?v=t-j6dtyYUBY
And below is a pic of the newest map:
http://www.historicalboardgaming.com/assets/images/Maps/Global 1939R/Global_new_revised_3.0.jpg
I’ve played Global '39 more than a dozen times and I love it more each game. Have fun!