I would look at shock mounts to see if they're broken/cracked, sway bar end links for same, front swaybar endlinks, ujoints, ball joints, etc.
I'm trying to track down a similar sounding noise in mine. It sounds like a bolt rolling in a pickup bed for a few rolls, but only on take off and only up to about 10-15 mph. If I ease into the takeoff up to about 10-15 then give it heavier gas it doesn't do it at all. I've got ball joints to replace up front that definitely need it, a broken link up front to remove/replace and then I'm out of ideas on mine. Good luck!