Indoors mostly but a group of 3-4 people.
Then you're set with the 24-70/2.8 II. More Speedlites aren't the best answer, either. Good lighting for a small group means big modifiers, so I'd start looking at monolights (the PCB Einstein is excellent, and cheaper than a 600EX-RT).
The 70-300L is a great travel telezoom, but IMO still not really long enough for wildlife.
Can you give me an example of a lighting setup so i could look into costs please?