Does anyone have any advice on what I can add to my chocolate to keep it from cracking & falling off the berry when bitten? I normally use Ghirardelli chips. I was thinking either cream or butter...am I on the right track? Thanks in advance!

I have the perfect solution for you. Sarah Bernhardt chocolate glaze, let it set up to about the consistency of Hersheys bottled ice cream syrup and dip the berries. They have a softer mouth feel than pure chocolate and they don't shatter when you bite into them.
http://www.cakecentral.com/cake_recipe-2315-Sarah-Bernhardt-Chocolate-Glaze.html

Here is a cake I made with dippped berries using this glaze.
http://www.cakecentral.com/modules.php?name=gallery&file=displayimage&pid=160683