We use Bomgar, which is pretty powerful. But good lord it's next to impossible to get packaged up for automatic deployment. And I'm certain it is NOT cheap. :-o
FWIW, it works great.
Here's their 'info' on packaging their client for deploying with Dell's KACE or Apple Remote Desktop. I can't get it to work. First we were out of date, and now we're too up-to-date on their server.
http://www.bomgar.com/docs/content/platforms/mac/mass-deploy-on-mac.htm
