Groups are given time, usually 5 minutes, to collaborate with their group on which country/region to select.
Each country / region has a "country paper" to keep track
Each "country paper" is individualized.
For example, largely populated countries / regions will have more infrastructure to build.
Who chooses first?
Consider walking around while groups are talking and have each group roll 2 dice.
Highest roll = 1st pick
2nd highest = 2nd pick