I would suggest you buy Joel Salatins book "Salad Bar Beef" This is a good start on eco agriculture. Pay particular attention to ponds and why they should be fenced off from animal and the water pumped out as needed or use stock tank with community water. You can get this book from www.acresusa.com
With 8 acres 3 llamas is all the animals you need if you have any idea of feeding them on grass without using hay year around.
I have a friend that runs llamas with here miniature cows to ward off wolves and other preditors - dogs, etc. Her llamas eat grass and hay just like her cows and they do very well.
Robert D Bard