Group calls with Asterisk (What is the best way?)

Hi Guys,

I have quick questions.
Hope somebody can send me in the right direction.

I want to create a system with Asterisk to make group calls.

For example

Extension 1000 will make multiple groups calls, after one group call is finished the next group will be invited.

Group 1 - extensions 1001, 1002, 1003, 1004
Group 2 - extensions 1005, 1006, 1007, 1008
Group 3 - extensions 1009, 1010, 1011, 1012

What would be the best way to create a group calling system like this.

I was thinking of a conference call and using the Asterisk Ami for originate calls.
Are there easier ways with Asterisk to create a system like this?

Thank you for your thoughts.

Wesley

AMI looks to be the best path for me and Local channels